AN11238 LPC11Cxx CANopen network demo
Contents
1. make sure to change this when using 2 slaves in ms CANopen error register LEDs of MCB11C14 board heartbeat producer value buffer structure associated with segmented entry 2200h buffer associated with segmented entry 2200h for watching nodes number of nodes in watchlist must be known constant OD entries required so that the number of entries in the constant OD is known non constant OD entries required so that the number of entries in the non constant OD is known Fig 21 Node definition header file for slave node All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 31 of 34 NXP Semiconductors AN11238 6 References LPC11Cxx CANopen network demo include CAN Node Def h include lt stdint h gt Application variables used in variable OD uint8_t error register uint8_t LEDArray volatile SDOS Buffer_t SDOS_2200 wint8_t SDOS_2200 Data sizeof SDOS 2200 Data ye volatile uint amp t SDOS_2200 Data 255 Boot up value of SDO 2200h uint32_t CANopen Heartbeat _Producer_ Value WatchNode _t WatchList 1i uint8_t WatchListLength sizeof WatchList sizeof WatchList 0 CANopen read only constant Object Dictionary OD entries Used with Expedited SDO only Lengths 1 2 4 bytes CAN_ODCONSTE2. Fig 20 Flowchart of the slave node After reset the hardware is initialized e g the LPC11Cxx and its peripherals LEDs UART etc After the hardware initialization is done the CANopen driver is initialized by calling the CANopenInit functions This function makes the CANopen driver ready for use and also calls the callback functions CANopen_Init_SDO thereby initializing the CANopen SDO parameters This also enables the production of the heartbeat every 4000 ms The CANopen_Init_SDO function can be called anytime upon receiving the NMT reset command After initializing the CANopen driver an endless loop is entered In this endless loop the software keeps checking the state of the buttons If any of the three buttons is pressed the appropriate action will be taken All other functions e g responding to CANopen messages and handling timeouts are performed by the timer interrupt and the CAN interrupt All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 29 of 34 NXP Semiconductors AN1 1 238 AN11238 LPC11Cxx CANopen network demo 5 3 CANopen driver To use the CANopen driver the file CANopen h should be included in the project A number of functions are present in the API for reading or writing to other nodes In order for the CANopen driver to work one should have the following prerequisites in its
3. Application note Rev 1 12 July 2012 7 of 34 NXP Semiconductors AN1 1 238 LPC11Cxx CANopen network demo The LPC11Cxx also provides on chip C_CAN drivers In addition to the CAN ISP the boot ROM provides a CAN and CANopen API to simplify CAN application development It covers initialization configuration basic CAN send receive as well as a CANopen SDO interface Callback functions are available to process received events This application makes use of these on chip CAN CANopen drivers thereby reducing development time and saving FLASH memory However the on chip CANopen driver does not fully implement all CANopen functions which are used by this demo so for the demo application an additional driver has been created This driver is generic for all CANopen functions and thus is shared among the master and slave software 3 Running the demo AN11238 3 1 Introduction As stated in chapter 2 three types of LPC11Cxx boards are supported The demo consists of several small programs which can be run in two ways e Some functions of the demo rely on the onboard LEDs and buttons of the Keil MCB11Cxx board e Some functions of the demo rely on the serial connection of the master node to a terminal program like PuTTY Note Though multiple boards are supported the MCB11Cxx is the only board on which the demo can be partially run without serial connection When using a board other than the MCB11Cxx there is no way
4. 3 SDO segment upload 4 SDO abort transfer t Toggle This bit should toggle on every frame of the segmented transfer n Indicates the number of data bytes which do not contain data I Last frame Indicates for segmented transfer that this is the last frame data Data bytes of segmented transfer All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 16 of 34 NXP Semiconductors AN11238 4 3 1 LPC11Cxx CANopen network demo Expedited read To perform an expedited read of OD entry 2000h sub index 0x00 the client issues an initiate upload command 3 bits 1 bit 2 bits 1 bit 1 bit 2 bytes 1 byte 4 bytes Index Subindex Data cs 2 reserved 0 n 0 e 0 s 0 0x2000 0x00 0x00 cs 2 indicates an upload request n 0 ass 0 e 0 not used as no data is transferred only a request s 0 no size indicated size is not mandatory for reading Index 0x2000 transfer of index 2000h Subindex 0x00 transfer of sub index 0x00 Data 0x00 should be zero when reading The server should respond with the following reply assuming the entry exists and has 1 data byte containing OxAA 3 bits 1 bit 2bits 1 bit 1 bit 2 bytes 1 byte 4 bytes Index Subindex Data cs 2 reserved 0 n 3 e 1 s 1 0x200
5. 6 When lt 7 data bytes are left for transfer the client sends the last frame 3 bits 1 bit 3 bits 1 bit 7 bytes cs 0 t n l 1 data cs 0 indicating SDO segment download t needs to be set to the inversed value of the previous frame n 7 number of data bytes present in data 1 this frame is the last frame for the segmented transfer data is loaded with the data to be written A capture of a segmented write can be found in Fig 14 Time Type ID DLC Data 44 4485 Data 601 8 2100 2200 2C 00 00 00 44 4495 Data 581 8 60 00 22 00 00 00 00 00 44 4504 Data 601 8 00 5468 69 73 20 69 73 44 4515 Data 581 8 20 00 22 00 00 00 00 00 44 4524 Data 601 8 10 20 61 20 6D 65 73 73 44 4534 Data 581 8 30 00 22 00 00 00 00 00 44 4544 Data 601 8 00 616765 2065 6E 74 44 4553 Data 581 8 20 00 22 00 00 00 00 00 44 4563 Data 601 8 10 65 72 65 64 20 66 72 44 4573 Data 581 8 30 00 22 00 00 00 00 00 44 4582 Data 601 8 00 6F 6D 20 7468 65 20 44 4593 Data 581 8 20 00 22 00 00 00 00 00 44 4602 Data 601 8 10 7465 72 6D 69 6E 61 44 4612 Data 581 8 30 00 22 00 00 00 00 00 44 4622 Data 601 8 OB 6C 00 00 00 00 00 00 44 4632 Data 581 8 20 00 22 00 00 00 00 00 Fig 14 Capture from master node writing to OD entry 2200h of slave node 1 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 22 of 34
6. ReadOnly and should be set to a value which is the maximum number of nodes which it is allowed to watch The other sub indexes are 4 bytes in size are ReadWrite and are encoded as follows bits 31 24 32 16 15 0 Value 0 Node ID Heartbeat time Encoding Unsigned8 Unsigned16 Node ID is the node ID of the node to watch Heartbeat time is the heartbeat consumer interval in milliseconds Index 1017h Heartbeat Producer OD entry 1017h only has a valid entry at sub index 0x00 This entry is ReadWrite and has a size of 2 bytes The value specified in these 2 bytes encoded as Unsigned16 is the heartbeat producer interval in milliseconds Heartbeat example The following example will demonstrate the heartbeat protocol Please see the logging of the CAN bus while running parts of the demo in Fig 18 1 Slave node 1 is configured by executing terminal command 1 The heartbeat producer time is set to 4000ms and the heartbeat consumer time is set to 4500ms 2 Both the master node and the slave node are producing a heartbeat Their status is Pre Operational 0x7F 3 By pressing button ISP of the slave node a heartbeat failure of the slave node is simulated 4 After 4500ms the master node detects the missing heartbeat and sends NMT command 0x82 130 Reset Communication to the slave node 5 In reaction to NMT command 130 the slave resets its communication parameter After completing the Initialization
7. applications e When the application is initializing function CANopenlnit must be called to initialize the CANopen driver and the CAN peripheral Functions CANopen_1ms_tick must be called every 1ms e CANopen_Init_SDO callback functions must be present in the application This functions is called when initializing the CANopen driver and on reset of the node e g by NMT command e CANopen_NMT_Reset_Node_Received callback functions must be present in the application This function is called on receiving the NMT command Reset Node e CANopen_NMT_Reset_Comm_Received callback functions must be present in the application This function is called on receiving the NMT command Reset Communication e CANopen_Heartbeat_Consumer_Failed callback function must be present in the application This functions is called when one of the node listed in the WatchList does not transmit its heartbeat on time e CANopen_NMT_Consumer_Bootup_Received callback functions must be present in the applications Please refer to the application source code main c of the master node and the description in the canopen_driver c file to see what functions are available and how to use them More information on the on chip CAN CANopen drivers can be found in chapter 17 of the LPC11Cxx User Manual 5 4 CANopen device definition The device definition defines what the OD looks like Two files are required for a complete definition e
8. with all faults basis for evaluation purposes only NXP Semiconductors its affiliates and their suppliers expressly disclaim all warranties whether express implied or statutory including but not limited to the implied warranties of non infringement merchantability and fitness for a particular purpose The entire risk as to the quality or arising out of the use or performance of this product remains with customer In no event shall NXP Semiconductors its affiliates or their suppliers be liable to customer for any special indirect consequential punitive or incidental damages including without limitation damages for loss of business business interruption loss of use loss of data or information and the like arising out the use of or inability to use the product whether or not based on tort including negligence strict liability breach of contract breach of warranty or any other theory even if advised of the possibility of such damages Notwithstanding any damages that customer might incur for any reason whatsoever including without limitation all damages referenced above and all direct or general damages the entire liability of NXP Semiconductors its affiliates and their suppliers and customer s exclusive remedy for all of the foregoing shall be limited to actual damages incurred by customer based on reasonable reliance up to the greater of the amount actually paid by customer for the product or five dollars US 5 00
9. 00 00 00 00 11 0954 Data 601 8 60 00 00 00 00 00 00 00 11 0964 Data 581 8 00 00 00 00 00 00 00 00 11 0975 Data 601 8 70 00 00 00 00 00 00 00 11 1556 Data 581 8 10 00 00 00 00 00 00 00 11 1566 Data 601 8 60 00 00 00 00 00 00 00 11 1576 Data 581 8 09 00 00 00 00 00 00 00 Fig 13 Capture from master node reading OD entry 2200h of slave node 1 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 20 of 34 NXP Semiconductors AN11238 4 3 4 Segmented write LPC11Cxx CANopen network demo 1 To perform a segmented write of OD entry 2200h sub index 0x00 the client first issues an initiate download command 3 bits 1 bit 2 bits 1 bit 1 bit 2bytes 1 byte 4 bytes Index Subindex Data cs 1 reserved 0 n 0 e 0 s 1 0x2200 0x00 length cs 1 indicates an download request n 0 as e 0 e 0 not used as no data is transferred only a request s 1 size indicated in data not mandatory to indicate length Index 0x2200 wants to write to index 2200h Subindex 0x00 wants to write to sub index 0x00 data number of bytes to write not mandatory to indicate length 2 The server should respond with the following reply assuming the entry exists 3 bits 1 bit 2 bits 1 bit 1 bit 2 bytes 1 byte 4 bytes cs 3 rese
10. 4 4 The NMT protocol 0 eee eeeeeeeeseeeeeeeneeeeeenees 23 4 4 1 NMT States iiien 23 4 4 1 1 VMITIALIZING oo eee ee eeeeeeesneeeeeeneeeeeeeeeeeenaeeeeeeaees 23 4 4 1 2 PreOperational ececeeeeeeseeeeteeeeeeeeteereaes 23 4 4 1 3 Operational eee eeeeeeeeeteneeteneeteneeeeneereaes 24 AAA StOPped evcceeei neta diate 24 4 4 2 NMT COMMANGA 0 eeeeeeeeseeeeeeeneeereneeeeeeeeeetees 24 4 5 The heartbeat protocol i c 24 4 5 1 The heartbeat frame 25 4 5 2 Associated OD entries a se 25 4 5 2 1 Index 1016 h Heartbeat Consumer 25 4 5 2 2 Index 1017h Heartbeat Producer 0 25 4 5 3 Heartbeat example eeeeeeseeeeeteeeeeeneeeeeees 25 5 SOMWANG iz siccsecescacctceacecsececeistseeesieecessecccsesdaaescess 27 5 1 Software organization cecceeseeeeeeeneeeees 27 5 2 APpliCatiOn eeseeeeeesseeeeesneeeeseneeeeeeneeenenaees 27 5 2 1 Masteina a E E 27 5 2 2 AWC E N E T EET 29 5 3 CANopen OTivel cecceeeseeeeeeeseneeeeneetenteteeereaes 30 5 4 CANopen device definition ceeeeeeeeee 30 6 References 0 eeeseseeeeseeeeeenseeeeeseeneeenseeeeeessnenensenes 32 7 Legal information ccssssessseeeessseeensseeneeneee 33 7 1 Definition See a wate 33 7 2 DiSCIAIMETS esris nispirus 33 7 3 Trademarks ier devs i gies nn 33 8 COMO Swiss cccci2 sscsedais cadet adescasccdeccesseteszataresseedeas 34 Please be aware that important notices concerning this document an
11. NXP Semiconductors AN1 1 238 LPC11Cxx CANopen network demo 4 4 The NMT protocol The NMT Network Management protocol is used for changing the NMT state of the CANopen nodes Any node in the network may send a NMT command to another node or all nodes by broadcasting in the network The node which sends the NMT command is referred to as Master while the node s addressed is are referred to as Slave s Fig 15 shows a graphical representation NM T Master NMT Slave NMT Slave NMT Slave Fig 15 NMT master slave structure 4 4 1 NMT states 4 4 1 1 Each NMT slave has a state machine consisting of four states These four states are shown in Fig 16 Fig 16 NMT state machine of an NMT slave Initializing After Power On all NMT slaves change their state to Initializing After internal initialization of the NMT slave the NMT slave changes its state to Pre Operational Besides this state change the NMT protocol is the only way to change the present state of an NMT slave When changing to Pre Operational it should send a bootup message The bootup message is a frame with COB ID 0x700 node id of NMT slave There is just one data byte encapsulated in the bootup frame with a fixed value of 0x00 4 4 1 2 PreOperational AN11238 In the pre operational state SDO communication is allowed while PDO communication is inhibited All information provided in this document is subj
12. WriteOnly and RW Read Write AN11238 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 13 of 34 NXP Semiconductors AN11238 4 2 The COB ID LPC11Cxx CANopen network demo As explained in chapter 1 1 a CAN frame consists of 11 identifier bits and 8 data bytes In CANopen the 11 identifier bits are known as the CAN Object Identifiers COB ID The COB ID specifies the CANopen protocol used for the current CAN frame Table 3 shows the predefined COB IDs Table 3 CANopen predefined CAN object identifiers COB ID Object Mandatory optional 0x000 NMT Mandatory 0x080 SYNC Optional 0x081 OxOFF EMERGENCY Optional 0x100 TIME STAMP Optional 0x181 Ox1FF PDO1 transmit Optional 0x201 0x27F PDO1 receive Optional 0x281 0x2FF PDO2 transmit Optional 0x301 0x37F PDO2 receive Optional 0x381 Ox3FF PDO3 transmit Optional 0x401 0x47 F PDO3 receive Optional 0x481 Ox4FF PDO4 transmit Optional 0x501 0x57F PDO4 receive Optional 0x581 0x5FF SDO transmit server Mandatory 0x601 0x67F SDO receive client Mandatory 0x701 0x77F NMT Error Control Mandatory AN11238 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 14 of 34 NXP Semiconductors AN1 1 2
13. of controlling the demo other than by the serial connection 3 2 Using the RS232 serial connection The demo board can be controlled by a RS232 serial connecting by starting a terminal application with the following settings e Baudrate 115200 e Databits 8 e Parity none e Stopbits 1 After booting up the master node prints a menu to the terminal which can be seen in Fig 6 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 8 of 34 NXP Semiconductors AN1 1 238 LPC11Cxx CANopen network demo r EP CANopen Demo ajE FO RRR RRR RRR RRR RRR RRR RRR RRRE CANopen Example V1 0 la RRR HREM HHH RHR RRR kkk kkk kkk kkkt Please enter one of the following commands 1 Configure slave node 1 2 Configure slave node 2 3 Read SDO slave node 1 4 Read SDO slave node 2 5S Write to SDO entry 2200h of slave node 1 6 Write to SDO entry 2200h of slave node 2 7 Write to LEDS of slave node 1 8 Write to LEDS of slave node 2 9 Copy LEDs of slave node 1 to master node 10 Copy LEDs of slave node 2 to master node 11 Simulate heartbeat failure of master node Command L Fig 6 On startup of the CANopen master node a menu is printed to the terminal By entering any of the command numbers 1 11 an action is performed Short summary of t
14. regarding the heartbeat protocol AN11238 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 26 of 34 NXP Semiconductors AN11238 5 Software LPC11Cxx CANopen network demo AN11238 5 1 5 2 5 2 1 Software organization Three IDE s are supported e Code Red LPCXpresso e Keil uVision e IAR EWARM The source code and project files are structured as in Table 4 Table 4 File structure used for the CANopen application Directory file Projects LPCXpresso Master zip Projects LPCXpresso Slave zip Projects Keil Master Projects Keil Slave Projects IAR Master Projects IAR Slave Software CMSIS Software Drivers src CANopen canopen_driver c Software Drivers src UART uart c Software Drivers src Retarget Software Drivers inc CANopen canopen_driver h Software Drivers inc CANopen rom_drivers h Software Drivers inc CANopen rom_driver_CAN h Software Drivers inc UART uart h Software Master src main c Software Master src CAN_Node_Def c Software Master inc CAN_Node_Def h Software Slave src main c Software Slave src CAN_Node_Def c Software Slave inc CAN_Node_Def h Description Project file of master node for LPCXpresso Project file of slave node for LPCXpresso Project directory of master node for Keil Project directory of slave node for Keil Project directory of master node for IAR Pro
15. state it enters the Pre Operational state again and sends the boot up message All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 25 of 34 NXP Semiconductors AN11238 LPC11Cxx CANopen network demo 6 Master node sees the boot up message and has remembered that there was a heartbeat failure at this node So it re configures the slave node with a value for the heartbeat producer and heartbeat consumer OD entries 7 Both the master and the slave produce a heartbeat again Time 2 2381 2 2391 2 2400 2 2410 2 4830 6 2380 6 4829 10 2381 10 4828 14 2380 14 4828 18 2381 18 4829 22 2381 22 4829 26 4829 26 7380 26 7384 26 7500 26 7510 26 7534 26 7544 30 4929 30 7502 34 4929 34 7502 Type ID DLC Data 601 8 Data 581 8 Data 601 8 Data 581 8 Data 77 1 Data 701 1 Data 77D 1 Data 701 1 Data 7m 1 Data 701 1 Data 77D 1 Data 701 1 Data 77 1 Data 701 1 Data PO Cee tom Data ee w Data 000 2 Data 701 1 Data 601 8 Data 581 8 Data 601 8 Data 581 8 Data 7m 1 Data 701 1 Data 77 1 Data 701 1 Data 2B 17 10 00 AO OF 00 00 60 17 10 00 00 00 00 00 1 23 16 100194117D00 60 16 100100000000 YAW AAA WWW AA ine SB o 2B 17 10 00 AO OF 00 00 60 17 10 00 00 00 00 00 6 23 16 10 0194 11 7D 00 60 16 100100000000 7F F7 JF JF Fig 18 Logging of the CAN bus during some actions
16. 0 0x00 OxAA cs 2 indicates an upload n 3 as only 1 data bytes is present and thus 3 data bytes are unused e 1 indicating expedited transfer s 1 size is indicated in n Index 0x2000 transfer of index 2000h Subindex 0x00 transfer of sub index 0x00 Data OxAA value of OD entry 0x2000 sub index 0x00 is OxAA A capture of an expedited read can be found in Fig 11 Time Type ID DLC Data 4 7833 Data 601 8 40 00 20 00 00 00 00 00 4 7843 Data 581 8 4F 00 20 00 AA 00 00 00 Fig 11 Capture from master node reading entry 2000h of slave node 1 AN11238 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 17 of 34 NXP Semiconductors AN1 1 238 LPC11Cxx CANopen network demo 4 3 2 Expedited write To perform an expedited write of OD entry 2000h sub index 0x00 with a single data byte 0x55 the client issues an initiate download command 3 bits 1 bit 2 bits 1 bit 1 bit 2 bytes 1 byte 4 bytes Index Subindex Data 0x2000 0x00 0x55 cs 1 reserved 0 n 3 e 1 s 1 cs 1 indicates an initiating download command n 3 as only 1 data bytes is written and thus 3 data bytes are unused e 1 indicating an expedited transfer s 1 size is indicated in n Index 0x2000 transfer of index 2000h Subindex 0x00 transfer of sub index 0x00 Data 0x55 byte to b
17. 38 LPC11Cxx CANopen network demo 4 3 The SDO protocol The SDO protocol is used for storing data in and retrieving data from the OD Any node in the network may ask another node to read or store data by SDO The initiator is referred to as client and the node to which the request has been sent to is referred to as server Fig 10 shows a graphical representation Peer to peer communication Fig 10 Object Dictionary definition of slave node As it can be seen in Table 3 COB IDs 0x601 0x67F are used by the client to communicate with the server and COB IDs 0x581 0x5FF are used by the server to communicate with the client The required COB ID can be calculated as follows Client COB ID 0x600 Node ID of server to reach broadcast not allowed Server COB ID 0x580 Node ID of client to reach broadcast not allowed Two types of SDO access exist e Expedited SDO This type of access is used to access any OD entry with size lt 4 bytes e Segmented SDO This type of access is used to access any OD entry with size gt 4 bytes with theoretically up to an infinite number of bytes The SDO protocol specifies five commands e SDO segment download e Initiating download e Initiating upload e SDO segment upload e Abort SDO transfer AN11238 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 1
18. 5 of 34 NXP Semiconductors AN11238 AN11238 LPC11Cxx CANopen network demo With these five commands data can be read from and written to the OD of an SDO server Two types of data structures are used for these five commands Format 1 Used for expedited transfer or for initiating a segmented transfer 3 bits 1 bit 2 bits 1 bit 1 bit 2 bytes 1 byte 4 bytes cs reserved 0 n e s index subindex data cs Command Specifier Indicates which command is used 0 SDO segment download 1 Initiating download 2 Initiating upload 3 SDO segment upload 4 SDO abort transfer n Indicates the number of data bytes which do not contain data only if both e and sare set e If set indicates an expedited transfer data is encapsulated in the 4 data bytes of the CAN frame If cleared transfer is of segmented type s If set data size is indicated in n e is set or data size is indicated in data e is cleared index index of OD entry subindex sub index of OD entry data if e is set data contains the data to transfer If e is cleared and s is set indicates the data size of the segmented transfer Format 2 Used for transferring segments of data while a segmented transfer is in progress 3bis 1bit 3bis 1bit 7bytes cs t n l data cs Command Specifier Indicates which command is used 0 SDO segment download 1 Initiating download 2 Initiating upload
19. AN11238 LPC11Cxx CANopen network demo Rev 1 12 July 2012 Application note Document information Info Content Keywords LPC11C12FBD48 LPC11C14FBD48 LPC11C22FBD48 LPC11C24FBD48 LPC11Cxx CAN CANopen on chip driver Abstract This application note illustrates how to use LPC11Cxx to setup a simple CANopen network using the on chip CAN CANopen drivers NXP Semiconductors AN1 1 238 LPC11Cxx CANopen network demo Revision history Rev Date Description 1 20120712 Initial release Contact information For additional information please visit http Avww nxp com For sales office addresses please send an email to salesaddresses nxp com AN11238 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 2 of 34 NXP Semiconductors AN1 1 238 LPC11Cxx CANopen network demo 1 Introduction This application note demonstrates the CAN peripheral and the on chip CAN CANopen drivers of the LPC11Cxx 1 1 CAN The Controller Area Network CAN is a serial asynchronous multi master communication protocol for connecting electronic control modules sensors and actuators in automotive and industrial applications Important features of CAN are e Very good signal integrity due to differential signaling e Collision and error detection and re transmission possibilities e Multiple masters can exist within
20. CAN_Node_Def c e CAN_Node_Def h These two files define multiply of things regarding the behavior of the CANopen node in particular e Its Node ID e Its Object Dictionary OD e Variables coupled to the OD e SDO Client timeout value e Watchlist used for initial guarding of nodes Fig 21 and Fig 22 show the node definition used for the slave node All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 30 of 34 NXP Semiconductors AN11238 AN11238 LPC11Cxx CANopen network demo ifndef _CAN_NODE_DEF_H idefine _CAN_NODE_DEF_ include lt stdint h gt include canopen_driver h define CAN_MASTER_NODE 0x7D 125 47 define CAN_SLAVE1_NODE 0x01 Ye a d define CAN_SLAVE2_NODE 0x02 ye any define CAN_NODE_ID CAN_SLAVE1_NODE idefine CANOPEN TIMEOUT_VAL 100 Application variables used in variable OD extern uint8_t error_register extern uint8_t LEDArray extern uint32_t CANopen _Heartbeat_Producer_ Value extern volatile SDOS_Buffer_t SDOS_2200 extern volatile uint8_t SDOS_2200_Data 255 Watchlist extern WatchNode t WatchList extern uint amp _t WatchListLength OD extern CAN_ODCONSTENTRY myConstOD extern uint32_t NumberOfmyConstODEntries extern CAN _ODENTRY myOD extern uint32_t NumberOfmyODEntries endif CAN NODE DEF H ye
21. EXP 0x00 0x00 0x00 0x00 0x01 2200H 00H SEG Boot up value of SDO 2200h ni IEB ee ee Finished executing command 3 RRR REE REE RRR RRR ERR RHR RRR Fig 7 Result of execution of command 3 5 amp 6 After selecting command 5 or 6 the user is asked to enter a string On pressing enter the string is sent to SDO entry 2200H of the specified slave The result can be verified by re reading the complete SDO of the specified slave An example is given in Fig 8 AN11238 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 10 of 34 NXP Semiconductors AN1 1 238 LPC11Cxx CANopen network demo P CANopen Demo bhaa 7 Write to LEDS of slave node 1 s 8 Write to LEDS of slave node 2 9 Copy LEDs of slave node 1 to master node 10 Copy LEDs of slave node 2 to master node 11 Simulate heartbeat failure of master node Executing command 3 Read SDO slave node 1 Node ID Index Subindex EXP SEG Size Data 0x01 1000H 00H EXP 4 0x00 0x00 0x00 0x00 0x01 1001H 00H EXP i 0x00 0x00 0x00 0x00 0x01 1016H 00H EXP 1 0x01 0x00 0x00 0x00 0x01 1016H 01H EXP 4 0x00 Ox7D 0x11 0x94 0x01 1017H 00H EXP 2 OxOF OxAO 0x00 0x00 0x01 1018H OOH EXP 1 0x01 0x00 0x00 0x00 0x01 1018H 01H EXP 4 0x00 0x00 0x02 OxDC 0x01 2000H 00H EXP i 0x00 0x00 0x00 0x00 0x01 2200H OOH SEG This is a message entered fr
22. NTRY myConstOD index subindex length value 0xi000 0x00 4 OxO00000000UL 0xi018 0x00 i 0x00000001UL 0xi018 0x01 4 Ox000002DCUL e only vendor ID is specified NXP vendor ID for CANopen uint32_t NumberOfmyConstODEntries sizeof myConstOD sizeof myConstOD 0 CANopen list of variable Object Dictionary OD entries Expedited SDO with length 1 2 4 bytes and segmented SDO CAN_ODENTRY myOD index subindex access type length 0x1001 0x00 OD_EXP RO 1 0x1016 0x00 OD EXP RO 1 0x1016 0x01 OD EXP RW 4 0x1017 0x00 OD_EXP RW 2 0x2000 0x00 OD_EXP RW 1 0x2200 0x00 OD_SEG RW he value_pointer uint8_t uint8_t uint8_t uint8_t uint8_t uint8_t amp error register amp WatchListLength amp WatchList 0 value amp CANopen_Heartbeat_Producer Value amp LEDArray amp SDOS_2200 uint32_t NumberOfmyODEntries sizeof myOD sizeof myOD 0 Fig 22 Node definition source file for slave node AN11238 1 _ CANopen Application Layer and Communication Profile CiA Draft Standard 301 Version 4 02 2 LPC11C12 C14 Data sheet 3 UM10398 LPC111x LPC11Cxx user manual All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 32 of 34 NXP Semiconducto
23. SP 401 Device Profile for VO Modules 3 Read State 8 Input Lines etc reserved Fig 1 General CANopen Object Dictionary structure AN11238 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 3 of 34 NXP Semiconductors AN1 1 238 AN11238 LPC11Cxx CANopen network demo The CANopen communication model defines four types of communication objects COB e Administrative message e Service Data Object SDO e Process Data Object PDO e Predefined messages or Special Function Objects An SDO provides the access to entries of a device OD PDO is used to transfer real time data Predefined messages or special function objects include synchronization time stamp emergency node life guarding and boot up The relation between CAN communication the Object Dictionary and application software on a CANopen device is schematically illustrated in Fig 2 CANopen device Communication Object Application Interface Dictionary PDOs Data Types Application SDOs Communication Program Special Function Objects Device Profile Objects Application Implementation NMT Objects Objects Fig 2 Schematic relationship between CAN bus communication Object Dictionary and application software on a CANopen device Different CAN identifiers support different communication objects called COB ID The pred
24. Semiconductors aggregate and cumulative liability towards customer for the products described herein shall be limited in accordance with the Terms and conditions of commercial sale of NXP Semiconductors Right to make changes NXP Semiconductors reserves the right to make changes to information published in this document including without limitation specifications and product descriptions at any time and without notice This document supersedes and replaces all information supplied prior to the publication hereof Suitability for use NXP Semiconductors products are not designed authorized or warranted to be suitable for use in life support life critical or safety critical systems or equipment nor in applications where failure or malfunction of an NXP Semiconductors product can reasonably be expected to result in personal injury death or severe property or environmental damage NXP Semiconductors and its suppliers accept no liability for inclusion and or use of NXP Semiconductors products in such equipment or applications and therefore such inclusion and or use is at the customer s own risk Applications Applications that are described herein for any of these products are for illustrative purposes only NXP Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification Customers are responsible for the design and operation of their applic
25. The foregoing limitations exclusions and disclaimers shall apply to the maximum extent permitted by applicable law even if any remedy fails of its essential purpose 7 3 Trademarks Notice All referenced brands product names service names and trademarks are property of their respective owners NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 33 of 34 NXP Semiconductors AN1 1 238 LPC11Cxx CANopen network demo 8 Contents 1 Introduction wisiccccesssscsesccuisesesscanenssiacacecssesancsascness 3 1 1 GAN eeror Min Se EE es 3 1 2 07AN 0 0 lt APOO 3 1 3 EPGIIGM fen ita cee 5 2 CANopen demo introduction cssseeceeee 6 3 Running the GOMO csssceesssseeeessseeeeseseeneneeeeees 8 3 1 Introduction 0 0 eeeeeeeeteeeeeeneeeeseneeeeeenaeeeeeeneeeeenees 8 3 2 Using the RS232 serial connection 68 8 3 3 Using the onboard buttons eee eeeeeee 12 4 CANopen in more detail csecsseeeseeeeees 13 4 1 Object dictionary s eeseeeeeeieeeeeeeeeeeeeeeseeeeeeee 13 4 2 The GOBEAD veidni iniaiaiai ia 14 4 3 The SDO protocol 0 0 eeeeeeeeeeeeeeeeeeeeeeeeeeeee 15 4 3 1 Expedited read ccesecceeesecceeesseeeeeeeeseeeenenees 17 4 3 2 Expedited Wiite c eesceeeseseeeeseneeeeeeneeeeenaees 18 4 3 3 Segmented ead eeeeecceeeseeseeeeeeeeeseneeesneeeeaes 19 4 3 4 Segmented write eecceeseeeeeeeeeeeeeeneeeeneeeeaes 21
26. artbeats referred to as heartbeat consumers A node may be both producer and consumer Fig 17 shows a graphical representation Producer Producer Producer Consumer Consumer Consumer Producer Producer Consumer Fig 17 Heartbeat producers and consumers A heartbeat producer sends a heartbeat frame on a regular interval 0 to 65535 ms A heartbeat consumer listens to one or more heartbeats and has a consumer time interval defined for every node If the consumer did not receive a heartbeat from a node within this consumer time interval it knows that that node is not working properly and will try to reset it by the NMT protocol All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 24 of 34 NXP Semiconductors AN11238 4 5 1 4 5 2 4 5 2 1 4 5 2 2 AN11238 4 5 3 LPC11Cxx CANopen network demo The heartbeat frame A heartbeat frame consists of a COB ID 0x700 node id of producer and a single data byte The data byte represents the NMT status 0 Boot up Chapter 4 4 4 Stopped 5 Operational 127 Pre Operational Associated OD entries The heartbeat protocol is controlled by two indexes in the OD e 1016h Heartbeat consumer e 1017h Heartbeat producer Index 1016 h Heartbeat Consumer OD entry 1016h is an array type Sub index 0x00 is an entry with 1 byte in size is
27. ations and products using NXP Semiconductors products and NXP AN11238 All information provided in this document is subject to legal disclaimers Semiconductors accepts no liability for any assistance with applications or customer product design It is customer s sole responsibility to determine whether the NXP Semiconductors product is suitable and fit for the customer s applications and products planned as well as for the planned application and use of customer s third party customer s Customers should provide appropriate design and operating safeguards to minimize the risks associated with their applications and products NXP Semiconductors does not accept any liability related to any default damage costs or problem which is based on any weakness or default in the customer s applications or products or the application or use by customer s third party customer s Customer is responsible for doing all necessary testing for the customer s applications and products using NXP Semiconductors products in order to avoid a default of the applications and the products or of the application or use by customer s third party customer s NXP does not accept any liability in this respect Export control This document as well as the item s described herein may be subject to export control regulations Export might require a prior authorization from competent authorities Evaluation products This product is provided on an as is and
28. d the product s described herein have been included in the section Legal information NXP B V 2012 All rights reserved For more information please visit http www nxp com For sales office addresses please send an email to salesaddresses nxp com Date of release 12 July 2012 Document identifier AN11238
29. e hardware initialization is done the CANopen driver is initialized by calling the CANopenInit functions This function makes the CANopen driver ready for use and also calls the callback functions CANopen_Init_SDO thereby initializing the CANopen SDO parameters This also enables the production of the heartbeat every 4000 ms The CANopen_Init_SDO function can be called anytime upon receiving the NMT reset command After the CANopen driver is fully initialized the menu with available commands is printed Next a loop is entered which waits for a command This command can come from the RS232 connection or from the buttons on the MCB11C14 board Upon entering a valid command it will be executed e g read SDO of slave and print it to the terminal After All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 28 of 34 NXP Semiconductors AN1 1 238 AN11238 LPC11Cxx CANopen network demo execution the result is printed to the terminal the menu is displayed and another command can be given to the master node 5 2 2 Slave Fig 20 shows the flowchart of the slave node Done nitialize CANopen driver Done Received NMT reset command nitializ CANopen SDO Done Done PIO1_4 pushed ISP pushed PIO1_5 pushed imulat Decrease ncreas heartbeat LED LED fail value value
30. e written The server should respond with the following reply assuming the entry exists 3bits 1 bit 2bits 1bit 1bit 2bytes 1byte 4bytes Index Subindex Data 0x2000 0x00 0x00 cs 3 reserved 0 n 0 e 0 0 cs 3 indicates an confirmation of the download n 0 as sis 0 e 0 as no data is transferred s 0 size is not indicated as no data is transferred Index 0x2000 transfer of index 2000h Subindex 0x00 transfer of sub index 0x00 Data 0x00 as no data is transferred A capture of an expedited write can be found in Fig 12 Time Type ID DLC Data 10 3294 Data 601 8 2F 00 20 00 55 00 00 00 10 3304 Data 581 8 60 00 20 00 00 00 00 00 Fig 12 Capture from master node writing single data byte 0x55 to OD entry 2000h of slave node 1 AN11238 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 18 of 34 NXP Semiconductors AN11238 4 3 3 Segmented read 1 To perform a segmented read of OD entry 2200h sub index 0x00 the client first issues an initiate upload command LPC11Cxx CANopen network demo 3 bits 1 bit 2 bits 1 bit 1 bit 2 bytes 1 byte 4 bytes Index Subindex Data cs 2 reserved 0 n 0 e 0 s 0 0x2200 0x00 0x00 cs 2 indicates an upload request n 0 ass 0 e 0 not used as no data i
31. ect to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 23 of 34 NXP Semiconductors AN1 1 238 LPC11Cxx CANopen network demo 4 4 1 3 Operational 4 4 1 4 AN11238 4 4 2 4 5 In the operational state both SDO and PDO communication are allowed Stopped In stopped mode both SDO and PDO communication are inhibited NMT command As stated before an NMT master may change the state of an NMT slave by sending an NMT command COB ID is used for sending the command The NMT command has two data bytes The first data byte is the Command Specifier CS and the second byte is the node ID to specify which node is addressed Node ID 0x00 is also allowed which is the broadcast ID On receiving an NMT command with Node ID 0x00 all NMT slaves should execute the NMT command CS can have a few predefined values 1 Start remote node 2 Stop remote node 128 Enter Pre Operational 129 Reset node 130 Reset Communication The two reset commands allow a full reset 129 reset node or to only reset the communication parameters 130 reset communication The heartbeat protocol The heartbeat protocol is part of the error control protocol and is used to check that a device is still working properly The heartbeat protocol defines one or more nodes in the network producing a heartbeat referred to as heartbeat producers It also defines one or more nodes watching for he
32. efined connection set defines PDO SDO emergency object and node error control identifier It also supports the broadcasting of NMT module control SYNC and time stamp objects Fig 3 shows the CAN identifier allocation scheme All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 4 of 34 NXP Semiconductors AN1 1 238 LPC11Cxx CANopen network demo Broadcast objects of the CANopen Predefined Master Slave Connection Set Function code Communication con parameters at OD index 0000 ee ee NMT Module Control j s 080h 1005h 1006h 1007h 0010 l00h 1012h 1013h Peer to Peer objects of the CANopen Predefined Master Slave Connection Set A Function code Communication Ojer Fimetion eo zE PDO 1 transmit 0011 181h 1FFh 1800h PDO 2 transmit 0101 281h 2FFh 1801h PDO 3 transmit 0111 381h 3FFh 1802h PDO 4 transmit 1001 481h 4FFh 1803h PDO 4 receive 1010 50lh 57Fh 1403h sd SDO transmit server SDO receive client 1100 60lh 67Fh 1200h NMT Error Control 1110 701h 77Fh 1016h 1017h Fig 3 CANopen predefined CAN identifiers For CANopen protocol details please refer to CANopen Application Layer and Communication Profile CiA DS301 1 3 LPC11Cxx Built around the Cortex M0 architecture LPC11Cxx is integrated with one C_CAN controller of
33. fering a low cost entry point for CAN based applications and on chip CAN CANopen drivers The LPC11Cxx has one C_CAN controller The C_CAN controller is designed to provide a full implementation of the CAN protocol according to the CAN Specification Version 2 0B The main features of the LPC11Cxx CAN peripheral e Conforms to protocol version 2 0 parts A and B e Supports bit rate of up to 1 Mbit s e Supports 32 Message Objects e Each Message Object has its own identifier mask e Provides programmable FIFO mode concatenation of Message Objects e Provides maskable interrupts e Supports Disabled Automatic Retransmission DAR mode for time triggered CAN applications e Provides programmable loop back mode for self test operation e On chip CAN CANopen drivers The CAN controller consists of a CAN core message RAM a message handler control registers and the APB interface For communication on a CAN network individual AN11238 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 5 of 34 NXP Semiconductors AN1 1 238 LPC11Cxx CANopen network demo Message Objects are configured The Message Objects and Identifier Masks for acceptance filtering of received messages are stored in the Message RAM All functions concerning the handling of messages are implemented in the Message Handler Those functions are the acceptance fil
34. function ISP Simulate heartbeat failure of the master Simulate heartbeat failure of node the slave node PIO1_4 Read SDO entry 2000H LED value of slave Decrease SDO entry 2000H node 1 and write this value to the LEDs of LED value by 1 the master node PIO1_5 Read SDO entry 2000H LED value of slave Increase SDO entry 2000H node 2 and write this value to the LEDs of LED value by 1 the master node Note If no CAN bus analyzer is connected and the master node is not connected to a terminal the effect of the heartbeat failure is hard to see In case of a heartbeat failure of a slave node the effect of resetting the communication can be seen as the LEDs reset to their default value 0x00 all LEDs off In case of a heartbeat failure of the master node the effect cannot be seen without a CAN bus analyzer or serial connection All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 12 of 34 NXP Semiconductors AN1 1 238 LPC11Cxx CANopen network demo 4 CANopen in more detail Chapter 1 2 describes some basics of CANopen this chapter will explore it in detail Central concept in CANopen is the Object Dictionary OD which will be explained first Several protocols are supported the type of protocol used in the frame can be determined by looking at the COB ID Chapter 1 2 The OD can be accessed by the SDO pr
35. ghts reserved Application note Rev 1 12 July 2012 11 of 34 NXP Semiconductors AN1 1 238 AN11238 LPC11Cxx CANopen network demo CANopen Demo rex Executing command 11 Simulate heartbeat failure of master node Master node has stopped sending its heartbeat Finished executing command 11 RRR RRR RRR REE REE kkk kkk kkk kkk kkkt kkkt kkk kkkt kkk Please enter one of the following commands 1 Configure slave node 1 2 Configure slave node 2 3 Read SDO slave node 1 4 Read SDO slave node 2 5 Write to SDO entry 2200h of slave node 1 6 Write to SDO entry 2200h of slave node 2 7 Write to LEDS of slave node 1 8 Write to LEDS of slave node 2 9 Copy LEDs of slave node 1 to master node 10 Copy LEDs of slave node 2 to master node 11 Simulate heartbeat failure of master node Notify Master received NMT command Reset Communication Notify Master received NMT command Reset Communication Fig 9 Result of execution of command 11 Master received NMT command Reset Communication from both slaves 3 3 Using the onboard buttons The demo can also be partially controlled by the onboard buttons Please see Table 1 for details of the functions that can be executed by the buttons Table 1 The demo can also be controlled by the onboard buttons This table shows how the functions are mapped to the buttons Button Master board function Slave board
36. hese actions are as given below 1 amp 2 Sets the heartbeat producer time of the specified slave to 4000 ms its heartbeat consumer time to 4500 ms and the heartbeat consumer node ID to the master s node ID This configures the slave to generate a heartbeat every 4000 ms and to track the heartbeat of the master node If the master does not send a heartbeat within every 4500 ms the slave node tries to reset the master node 3 amp 4 Read the full SDO of the specified slave node and prints it to the terminal Fig 7 shows the text from the terminal when reading the SDO of slave node 1 after configuring it AN11238 All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 9 of 34 NXP Semiconductors AN1 1 238 LPC11Cxx CANopen network demo 6 Write to SDO entry 2200h of slave node 2 7 Write to LEDS of slave node 1 8 Write to LEDS of slave node 2 9 Copy LEDs of slave node 1 to master node 10 Copy LEDs of slave node 2 to master node Simulate heartbeat failure of master node Node ID Index Subindex EXP SEG Size Data 0x01 1000H OOH EXP 4 0x00 0x00 0x00 0x00 0x01 1001H 00H EXP 0x00 0x00 0x00 0x00 0x01 1016H 00H EXP 0x01 0x00 0x00 0x00 0x01 1016H 01H EXP 0x00 Ox7D 0x11 0x94 0x01 1017H 00H EXP OxOF OxAO 0x00 0x00 0x01 1018H 00H EXP 0x01 0x00 0x00 0x00 0x01 1018H 01H EXP 0x00 0x00 0x02 OxDC 0x01 2000H 00H
37. ject directory of slave node for IAR CMSIS source files CANopen driver source UART driver source Source directory for retargeting printf and scanf CANopen driver header On chip drivers header On chip CAN driver header UART driver header Application source for master node Node definition source file for master node Node definition header for master node Application source for slave node Node definition source file for slave node Node definition header for slave node Application For both the master and the slave node most of the work is done by the CANopen driver Chapter 5 3 The CANopen device definition Chapter 5 4 also has an important role in the software This chapter explains on a higher level how the software behaves Master Fig 19 shows the flowchart of the master node All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 27 of 34 NXP Semiconductors AN1 1 238 AN11238 LPC11Cxx CANopen network demo Oe Done nitialize CANopen driver Done nitializ CANopen SDO Received NMT reset command Done i Invalid CMD enterd Done a Done Valid CMD entered i Done i amp Fig 19 Flowchart of the master node After reset the hardware is initialized e g the LPC11Cxx and its peripherals LEDs UART etc After th
38. ment is subject to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 19 of 34 NXP Semiconductors AN11238 AN11238 LPC11Cxx CANopen network demo 5 Steps 3 and 4 are repeated with the tbit been toggled every frame until the server is ready to send the last frame 6 When lt 7 data bytes are left for transfer the server sends the last frame 3 bits 1 bit 3 bits 1 bit 7 bytes cs 0 l 1 data cs 0 indicating SDO segment download t needs to be set to the inversed value of the previous frame n 7 number of data bytes present in data 1 this frame is the last frame for the segmented transfer data is loaded with the data present at index 2200h sub index 0x00 A capture of a segmented read can be found in Fig 13 Time Type ID DLC Data 11 0815 Data 601 8 40 00 22 00 00 00 00 00 11 0825 Data 581 8 40 00 22 00 00 00 00 00 11 0835 Data 601 8 60 00 00 00 00 00 00 00 11 0844 Data 581 8 00 42 6F 6F 74 2D 75 70 11 0854 Data 601 8 70 00 00 00 00 00 00 00 11 0864 Data 581 8 10 20 76 61 6C 7565 20 11 0874 Data 601 8 60 00 00 00 00 00 00 00 11 0883 Data 581 8 00 6F 66 20 53 44 4F 20 11 0894 Data 601 8 70 00 00 00 00 00 00 00 11 0903 Data 581 8 10 32 32 30 30 68 00 00 11 0914 Data 601 8 60 00 00 00 00 00 00 00 11 0924 Data 581 8 00 00 00 00 00 00 00 00 11 0934 Data 601 8 70 00 00 00 00 00 00 00 11 0944 Data 581 8 10 00 00 00
39. om t he terminal al Finished executing command 3 RRR RRR RRR RRR RRR RRR RRR RRR RRR RRR RRR RRR RRR RRR RRR RE RRR RRR RRR RRR RRR RRR RRR RRR RRR RRR Fig 8 Result of execution of command 3 after previously changing SDO entry 2200H by command 5 7 amp 8 By writing to SDO entry 2000H of the slave nodes their LEDs GPIO2 can be controlled After selecting command 7 or 8 the user is asked to enter a hexadecimal value After entering the same and pressing enter the hexadecimal value is sent to the SDO entry 2000H of the specified slave node The slave node copies the value of SDO entry 2000H to the LEDs GPIO2 every 1 ms Reading the SDO of the specified slave shows the written hexadecimal value in SDO entry 2000H 9 amp 10 Reads SDO entry 2000H of specified slave and copies this value to the LEDs GPIO2 of the master node 11 On start up of the master node it immediately starts sending its heartbeat every 4000 ms By executing command 11 the master node stops sending its heartbeat thereby simulating a failing master node If one or more slave nodes have been configured by command 1 and 2 the configured slave node s will send the NUT command Reset Communication after detection of the missing heartbeat Fig 9 shows the output of the terminal after the NMT command has been received AN11238 All information provided in this document is subject to legal disclaimers NXP B V 2012 All ri
40. one network allowing intelligent and redundant systems A CAN frame exists of 11 identifier bits and 8 data bytes CAN does not specify the meaning of these identifier bits nor the meaning of the data bytes A high level protocol is necessary for this 1 2 CANopen CANopen is a type of high level protocol for CAN bus suitable for embedded networks It is built on top of CAL using a subset of CAL services and communication protocols It provides an implementation of a distributed control system using the services and protocols of CAL The central concept in CANopen is the device Object Dictionary OD For every node in the network there exists an OD The OD contains all parameters describing the device and its network behavior The OD is an ordered grouping of objects each object is addressed using a 16 bit index To allow individual elements of structures of data to be accessed an 8 bit sub index has been defined as well Fig 1 shows the general layout of CANopen OD CANopen Object Dictionary a aed a T 0000 0001 OOI1F Static Data Types standard data types e g Boolean Integer16 0020 003F Complex Data Types predefined structures composed of standard data types e g PDOCommPar SDOParameter 005F 00A0 OFFF IFFF i reserved Communication Profile Area e g Device Type Error Register Number of PDOs supported 2000 5FFF OFFF Standardised Device Profile Area e g D
41. otocol which is described next Finally more info regarding the NMT protocol and the heartbeat protocol are given These functions are explained with the aid of screenshots of the CAN bus analyzer while sniffing the traffic generated by the CANopen demo 4 1 Object dictionary As explained in chapter 1 2 the OD contains all parameters describing the device and its network behavior The OD can be seen as a big register containing a number of items which can be referenced to by a 16 bit index and an 8 bit sub index The OD has a defined structure as can be seen in Table 2 Table 2 General CANopen Object Dictionary structure CANopen object dictionary Index Object 0000 not used 0001 001F Static Data Types standard data types e g Boolean Integer16 0020 003F Complex Data Types predefined structures composed of standard data types e g PDOCommPar SDOParameter 0040 005F Manufacturer Specific Complex Data Types 0060 007F Device Profile Specific Static Data Types 0080 009F Device Profile Specific Complex Data Types 00A0 OFFF reserved 1000 1FFF Communication Profile Area e g Device Type Error Register Number of PDOs supported 2000 5FFF Manufacturer Specific Profile Area 6000 9FFF Standardized Device Profile Area e g DSP 401 Device Profile for I O Modules 3 Read State 8 Input Lines etc A000 FFFF reserved Entries in the OD can be marked as RO ReadOnly WO
42. rs AN11238 7 Legal information LPC11Cxx CANopen network demo 7 1 Definitions Draft The document is a draft version only The content is still under internal review and subject to formal approval which may result in modifications or additions NXP Semiconductors does not give any representations or warranties as to the accuracy or completeness of information included herein and shall have no liability for the consequences of use of such information 7 2 Disclaimers Limited warranty and liability Information in this document is believed to be accurate and reliable However NXP Semiconductors does not give any representations or warranties expressed or implied as to the accuracy or completeness of such information and shall have no liability for the consequences of use of such information NXP Semiconductors takes no responsibility for the content in this document if provided by an information source outside of NXP Semiconductors In no event shall NXP Semiconductors be liable for any indirect incidental punitive special or consequential damages including without limitation lost profits lost savings business interruption costs related to the removal or replacement of any products or rework charges whether or not such damages are based on tort including negligence warranty breach of contract or any other legal theory Notwithstanding any damages that customer might incur for any reason whatsoever NXP
43. rved 0 n 0 e 0 s 0 Index 0x2200 Subindex 0x00 Data 0x00 cs 3 indicates an acknowledge n 0 as sis 0 e 0 indicating a segmented transfer s 0 size is not indicated Index 0x2200 transfer of index 2200h Subindex 0x00 transfer of sub index 0x00 Data 0x00 as no data in transferred in this frame 3 The client may now send the data to be written 3 bits 1 bit 3 bits cs 0 t 0 n 0 cs 0 indicating SDO segment download t 0 toggle bit starts at 0 7 bytes data n 0 all 7 data bytes contain data 0 this frame is not the last frame for the segmented transfer data is loaded with the data to be written AN11238 All information provided in this document is subject to legal disclaimers Rev 1 12 July 2012 NXP B V 2012 All rights reserved 21 of 34 Application note NXP Semiconductors AN11238 AN11238 LPC11Cxx CANopen network demo 4 The server should respond with an acknowledge 3 bits 1 bit 3 bits 7 bytes cs 1 t 0 n 0 data cs 1 indicating an acknowledge t 0 toggle bit starts at 0 n 0 not used for acknowledge 0 this not used for acknowledge data is don t care when for acknowledge Steps 3 and 4 are repeated with the tbit been toggled every frame until the client is ready to send the last frame
44. s transferred only a request s 0 no size indicated size is not mandatory for reading Index 0x2200 wants to read from index 2200h Subindex 0x00 wants to read from sub index 0x00 Data 0x00 should be zero when reading 2 The server should respond with the following reply assuming the entry exists 3 bits 1 bit 2bits 1 bit 1 bit 2 bytes 1 byte 4 bytes cs 2 reserved 0 n 0 e 0 s 0 Here mets ax ee cs 2 indicates an upload n 0 as sis 0 e 0 indicating a segmented transfer s 0 size is not indicated Index 0x2200 transfer of index 2200h Subindex 0x00 transfer of sub index 0x00 Data 0x00 as no data in transferred in this frame 3 The client needs to send an acknowledge to the server 3 bits 1 bit 3 bits 1 bit 7 bytes cs 3 t 0 n 0 l 0 data 0x00 cs 3 indicating an acknowledge t 0 toggle bit starts at 0 n 0 not used with acknowledge 0 not used with acknowledge data 0x00 not used with acknowledge 4 The server responds with the first set of data 3 bits 1bit 3 bits 1bit 7 bytes cs 0 t 0 n 0 l 0 data cs 0 indicating SDO segment download t 0 toggle bit starts at 0 n 0 all 7 data bytes contain data 0 this frame is not the last frame for the segmented transfer data is loaded with the data present at index 2200h sub index 0x00 AN11238 All information provided in this docu
45. tering the transfer of messages between the CAN Core and the Message RAM and the handling of transmission requests as well as the generation of the module interrupt The register set of the CAN controller can be accessed directly by an external CPU via the APB bus These registers are used to control configure the CAN Core and the Message Handler and to access the Message RAM CAN_TXD CAN_RXD CAN CORE Ss MESSAGE RAM MESSAGE HANDLER APB bus APB INTERFACE REGISTER INTERFACE Fig 4 C_CAN block diagram 2 CANopen demo introduction AN11238 The demo requires a minimum of two LPC11Cxx boards Three types of LPC11Cxx boards are supported e Keil MCB11C14 full support e IAR LPC11C14 SK not all demo functions are supported e LPCXpresso LPC11C24 not all demo functions are supported Additionally a third LPC11Cxx board can be connected to create a larger network Three IDE s are supported e Code Red LPCXpresso tested with V4 1 5 e Keil pVision tested with V4 23 e AR EWAR M tested with V6 30 The master node requires about 22 kB of flash and 1 5 kB of RAM The slave node only requires about 5 kB of flash and 1 5 kB of RAM The big difference between the two is because the master node application uses the full printf and scanf functions The master node and the slave node share the same CANopen library which is quite small All information provided in this document is subject
46. to legal disclaimers NXP B V 2012 All rights reserved Application note Rev 1 12 July 2012 6 of 34 NXP Semiconductors AN1 1 238 AN11238 LPC11Cxx CANopen network demo For a fully functional demo the following setup is required Fig 5 e One MCB11C14 board flashed with the master software e Two MCB11C14 boards flashed with slave software both boards should have unique CAN_NODE_ID e Master board must be connected to a computer s serial port running a terminal program e g PuTTY e To see what data is transmitted over the CAN bus a CAN bus analyzer is highly recommended gt T F Slave node 2 e ram 1 ai w wv U bred s 4 Slave node 1 Serial connection of master node Fig 5 Demo setup with three Keil MCB11C14 boards The USB cables are only used for supplying power to the boards Not all features of CANopen are implemented in the demo but the most used features of CANopen are supported e SDO expedited transfer client amp server e SDO segmented transfer client amp server e NMT master slave amp boot up e Heartbeat producer amp consumer The demo will demonstrate these features with the aid of a terminal program and the onboard LEDs and buttons PDO transfer synchronization time stamp and emergency are not realized in the demo All information provided in this document is subject to legal disclaimers NXP B V 2012 All rights reserved
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