Micro488/p User`s Manual
Contents
1. H 1 Turn on hardware handshake PRINT IeeeOut X 0 Turn off XON XOFF handshake PRINT IeeeOut TC 2 Set serial terminator to CR PRINT IeeeOut TB 4 Set IEEE bus terminator to CR LF t TIMER DO WHILE t 5 gt TIMER Wait 5 seconds LOOP aS INPUTS LOC 1 fleeeln Clear the serial input buffer Appendix C Sample Initialization Program 09 27 02 C 1 Notes C 22. Command Descriptions 09 27 02 3 13 I INIT The system command INIT provides a warm start of the interface Issuing the INIT command clears the serial input pending commands and output pending data buffers and re initializes the internal IEEE controller hardware SYNTAX I RESPONSE None BUS STATES IFC REN IFC ATN REN REN EXAMPLE PRINT 1 I L LOCAL The LOCAL command without optional address causes the Micro488 p to un assert the Remote Enable line causing devices on the bus to return to manual operation With the address specified the bus device is placed in the local mode by the Go To Local GTL bus command SYNTAX L addr RESPONSE None BUS STATES REM unaddressed ATN UNL UNT LAG GTL addressed EXAMPLES PRINTH1 L Un assert the REN Line PRINT 1 L 16 Cause device 16 to go to local 3 14 09 27 02 Command Descriptions LL LOCAL LOCKOUT The LOCAL LOCKOUT command causes the Micro488 p to issue a Local Lockout IEEE bus command which inhibits bus devices that support this command from being controlled manually from their front panels SYNTAX LL RESPONSE None BUS STATES ATN LLO EXAMPLES PRINT 1 LL Send Local Lockout command O OUTPUT The OUTPUT command sends data to the IEEE bus The Remote Enable line is first asserted then if a device address is specified that device is addressed to listen If an address is not specified the Micro488 p must already be configured to send data as a res
3. instructs the Micro488 p to either enable or disable serial echo SYNTAX RESPONSE BUS STATES EXAMPLE 3 10 EC n n 1 enable serial echo n 0 disable serial echo None None PRINT 1 EC 1 Enable serial echo 09 27 02 Command Descriptions EN ENTER The ENTER command reads data from the IEEE bus If a device address is specified that device is addressed to talk If no address is specified the Micro488 p must already be configured to receive data as a result of an immediately preceding ENTER command The Micro488 p hangs the bus if no device is present to provide the data From either mode addressed or unaddressed the Micro488 p inputs data from the IEEE bus and sends it to serial port until one of the following conditions is met l A terminator character is received from the IEEE device that is talking 2 AnEOl is received with the data from the IEEE device that is talking 3 An Escape command is received from the host computer via the serial port SYNTAX EN addr addr is the IEEE bus device address RESPONSE Device dependent data The response ends when the IEEE bus input terminator is detected and the serial output terminators are appended to the returned data BUS STATES ATN UNL TAG ATN Micro488 p is in the listener active state and IEEE device is in the talker active state EXAMPLES PRINT 1 EN 16 Read data from device 16 INPUT 1 AS PRINT 1 EN 16 LINE INPUT 1 AS Read an entire line
4. is specified then GET only affects those devices that are already in the listen state as a result of a previous OUTPUT command SYNTAX TR addr RESPONSE None BUS STATES ATN GET unaddressed ATN UNL UNT LAG GET addressed EXAMPLES PRINT 1 TR 16 Issue Group Execute Trigger to device 16 3 18 09 27 02 Command Descriptions X XOFF XON The system command XOFF XON enables or disables XON XOFF handshaking SYNTAX RESPONSE BUS STATES EXAMPLE lt CTRL gt S X n n 0 disable XON XOFF handshaking n 1 enable XON XOFF handshaking None None PRINT 1 X 1 Enable XON XOFF handshaking XOFF The system command XOFF temporarily inhibits serial transmission from the Micro488 p SYNTAX RESPONSE BUS STATES EXAMPLE Command Descriptions lt CTRL gt S or CHR 19 None None PRINT 1 CHR 19 09 27 02 3 19 lt CTRL gt Q XON The system command XON restarts serial transmission from the Micro488 p following reception of the XOFF command SYNTAX lt CTRL gt Q CHR 17 RESPONSE None BUS STATES None EXAMPLE PRINT 1 CHRS 17 3 20 09 27 02 Command Descriptions Appendix A Command A L ML MT E UL UT ABORT VO DEVICE CLEAR ECHO ENTER ESCAPE HARDWARE HANDSHAKE IEEE BUS TERMINATOR INIT Appendix A Micro488 p Command Summary Code A L ML MT T addr UL UT C addr EC n ENTERJ addr lt CTRL gt A
5. off the IEEE bus SYNTAX UL RESPONSE None BUS STATES ATN UNL EXAMPLE PRINTHL 7 UL 3 8 09 27 02 Command Descriptions UT The UT command is a low level IEEE command which sends the UNT command to the IEEE bus This command instructs all devices on the IEEE bus to get off the IEEE bus SYNTAX RESPONSE BUS STATES EXAMPLE A UT None ATN UNT PRINT 1 UT ABORT VO The ABORT VO command causes the Interface Clear IFC bus management line to be pulsed By asserting IFC the Micro488 p regains control of the bus even if one of the devices has locked it up during a data transfer ABORT VO forces all IEEE bus device interfaces into a quiescent idle state SYNTAX RESPONSE BUS STATES EXAMPLE Command Descriptions A None REN IFC IFC ATN REN PRINT 1 A 09 27 02 3 9 C DEVICE CLEAR The DEVICE CLEAR command causes the Device Clear DCL bus command to be issued by the Micro488 p If the optional addresses are included the Selected Device Clear SDC command is issued to the specified devices IEEE 488 bus devices which receive a Device Clear or Selected Device Clear command normally reset to their power on state SYNTAX RESPONSE BUS STATES EXAMPLES EC C addr None ATN DCL all devices ATN UNL UNT LAG SDC selected devices PRINT 1 cC Issue a Device Clear to all devices PRINT 1 C 10 Issue a Selected Device Clear to device 10 ECHO The system command ECHO
6. w device specified RESUME SERIAL POLL SRQ CHECK TRIGGER TRIGGER w device specified LOW LEVEL COMMAND SEND LISTEN ADDRESS w device specified LOW LEVEL COMMAND LOW LEVEL COMMAND SEND TALK ADDRESS w device specified LOW LEVEL COMMAND LOW LEVEL COMMAND 09 27 02 3 1 System Commands 3 2 3 2 1 lt CTRL gt A ESCAPE lt CTRL gt O XON lt CTRL gt S XOFF EC n ECHO H n HARDWARE HANDSHAKE I INIT TB n IEEE BUS TERMINATOR TC n SERIAL TERMINATOR X n XOFF XON Command Description Format Each command description includes syntax response bus states and examples Syntax The syntax portion of the command description describes the proper command syntax which must be sent to the Micro488 p using the IBM BASIC PRINT command or its equivalent in other languages to the COM port The following conventions apply throughout the syntax descriptions The Micro488 p is case insensitive 1 e system commands may be in upper or lower case Commands to an individual IEEE device must conform to the device s particular syntax Items in lower case such as addr or n represent parameters which must be substituted with an appropriate value Numeric parameters those that are given as numbers are decimal unless preceded by amp H in which case they considered to be hexadecimal For example 00 is decimal 100 amp H64 is hexadecimal 64 which equals decimal 100 amp HFF is decima
7. 0 and 19200 Data Format 8 data bits 1 or 2 stop bits no parity Duplex Full with Echo No Echo Serial Control Selectable CTS RTS or XON XOFF Terminators Selectable CR LF LF CR and CR LF Connector 25 pin Sub D male RS 232C DCE Configured General Data Buffer 120 character input buffer Power Draws less than 5mA from the DTR or DSR serial lines on the host computer Max Dimensions 50mm x 60mm x 25mm 2 x 2 3 x 0 9 Weight 51 2 grams 1 8 oz Environment 0 to 50 C 0 to 90 R H non condensing Controls All settings auto or software configurable Note Specifications subject to change without notice 1 2 09 26 02 Micro488 p Introduction 1 4 Abbreviations The following IEEE 488 abbreviations are used throughout this manual addr n ATN CR data DCL GET GTL LAG LF LLO MLA MTA REN SDC SPD SPE SRQ TA TAD term UNL UNT x Micro488 p Introduction IEEE bus address n Attention line Carriage Return Data String Device Clear Group Execute Trigger Go To Local Listen Address Group Line Feed Local Lock Out My Listen Address My Talk Address Remote Enable Selected Device Clear Serial Poll Disable Serial Poll Enable Service Request Talker Active Talker Address Terminator Unlisten Untalk Unasserted 09 26 02 1 3 Notes 1 4 09 26 02 Micro488 p Introduction Getting Started 2 1 2 2 Inspection The Micro488 p was carefully inspected both mechanic
8. CHRS 1 Micro488 p Command Summary Description Asserts the attention line leaves Micro488 p in the controller active state Sends the LAG command to the specified device leaves Micro488 p in the controller active state Places the Micro488 p in the listen state on RESUME RS Places the Micro488 p in the talk state on RESUME RS Issues the talk command to the specified IEEE device Sends the UNL command to the IEEE bus instructs all devices on the IEEE bus to get off the IEEE bus Sends the UNT command to the IEEE bus instructs all devices on the IEEE bus to get off the IEEE bus Pulses Interface Clear IFC bus management line to be pulsed forces all IEEE bus device interfaces into a quiescent idle state Instructs Micro488 p to issue Device Clear DCL bus command if optional addresses are included issues the Selected Device Clear SDC command to the specified devices Instructs the Micro488 p to enable or disable serial echo Reads data from the IEEE bus and sends it to serial port a terminator character an EOI or an ESCAPE command terminates data input output Unlocks the Micro488 p from an inappropriate command clears the serial input pending commands and instructs Micro488 p to wait for new commands Enables or disables hardware CTS RTS handshake Selects the IEEE bus terminator for reads from the IEEE bus selected terminator signifies the end of an ENTER sequence Provides a warm start of the
9. Micro488 p User s Manual the smart approach to instrumentation IOtech Inc 25971 Cannon Road Cleveland OH 44146 1833 Phone 440 439 4091 Fax 440 439 4093 E mail Product Information sales iotech com E mail Technical Support productsupport iotech com Internet www iotech com Micro488 p User s Manual p n 223 0901 Rev 2 0 1992 by lOtech Inc October 2002 Printing Revised per EO 1634R1 ii Warranty Information Your IOtech warranty is as stated on the product warranty card You may contact IOtech by phone fax machine or e mail in regard to warranty related issues Phone 440 439 4091 fax 440 439 4093 e mail sales iotech com Limitation of Liability IOtech Inc cannot be held liable for any damages resulting from the use or misuse of this product Copyright Trademark and Licensing Notice All IOtech documentation software and hardware are copyright with all rights reserved No part of this product may be copied reproduced or transmitted by any mechanical photographic electronic or other method without IOtech s prior written consent IOtech product names are trademarked other product names as applicable are trademarks of their respective holders All supplied IOtech software including miscellaneous support files drivers and sample programs may only be used on one installation You may make archival backup copies FCC Statement IOtech devices emit radio frequency energy in
10. alizing OPEN COM1 19200 N 8 2 cs ds FOR RANDOM AS 1 t TIMER DO WHILE t 1 gt TIMER LOOP FORi 1TO5 PRINT 1 CHR 13 t TIMER DO WHILE t 2 gt TIMER LOOP NEXT i PRINT 1 I PRINT 1 EC 0 PRINT 1 H 1 PRINT 1 X 0 PRINT 1 TC 2 PRINT 1 TB 4 t TIMER Getting Started 09 26 02 DO WHILE t 5 gt TIMER LOOP a INPUT LOC 1 1 PRINT Ready DO IF LOC 1 THEN PRINT INPUT LOC 1 1 k INKEY PRINT 1 k PRINT k LOOP Section 3 contains detailed command descriptions which are applicable Micro488 p 2 8 09 26 02 Getting Started Command Descriptions 3 1 Introduction This section contains detailed descriptions of each of the low and high level commands available for the Micro488 p There are two types of commands bus commands and system commands Bus commands communicate with the IEEE 488 bus System commands configure or request information from the Micro488 p Bus Commands A C C lt addr gt EO n EN EN lt addr gt L L lt addr gt LL O cmd OA lt addr gt cmd RE RE lt addr gt RS SP lt addr gt SQ TR TR lt addr gt A L lt addr gt ML MT T lt addr gt UL UT Command Descriptions ABORT I O DEVICE CLEAR DEVICE CLEAR w device specified EOI ENABLE DISABLE ENTER ENTER w device specified LOCAL LOCAL w device specified LOCAL LOCKOUT OUTPUT OUTPUT w device specified REMOTE REMOTE
11. ally and electrically prior to shipment When you receive the interface carefully unpack all items from the shipping carton and check for any obvious signs of physical damage which may have occurred during shipment Immediately report any such damage found to the shipping agent Remember to retain all shipping materials in the event that shipment back to the factory becomes necessary Every Micro488 p is shipped with the following e Micro488 p IEEE488 Bus Controller e Micro488 p User s Manual p n 232 0901 Serial Configuration Some of the Micro488 p serial communication parameters are pre configured and can not be changed The following list describes the parameters which are fixed and therefore can not be changed Parameter sid Setting _ O Z Z OZ Oo O o O Data Bits 8 Bit ASCII Stop Bits The rest of the parameters are configured through software after power on The following is a list of the software configurable parameters Parameter Setting O Baud Rate 300 1200 2400 4800 9600 19200 Full with echo no echo Transmit Terminator LF CR LF CR CR LF Handshaking XON XOFF or CTS RTS Getting Started 09 26 02 2 1 2 3 2 2 Serial Signal Descriptions The Micro488 p serial connector is configured as DCE type equipment for RS 232 communications This means the Micro488 p always transmits data on Pin 3 and always receives data on Pin 2 Note that the Micro488 p is equipped with a standard DB 25S conn
12. e normally performed in response to assertion of the Service Request SRQ bus signal by some bus device SYNTAX SP addr RESPONSE 0 to 255 BUS STATES ATN UNL TAG SPE ATN data ATN SPD UNT EXAMPLES PRINT 1 SP 16 Serial Poll device 16 INPUT 1 SPSTAT Receive the Spoll status TC SERIAL TERMINATOR The SERIAL TERMINATOR command sets the end of line terminators for input from the serial host All input from the serial host must be terminated by the selected terminator During INPUT the Micro488 p takes the data it receives from the bus device until 1t detects the LF of other optionally specified input terminating condition It strips all CR and LF from the input data and appends the serial output terminator CR before sending it to the serial host The available terminators are 1 LF 2 CR 3 LF CR 4 CR LF SYNTAX TC n n is one of the available terminator types RESPONSE None BUS STATES None EXAMPLES PRINT 1 TC 2 Select CR as the serial output terminator Command Descriptions 09 27 02 3 17 SQ SRQ CHECK The system command SRQ CHECK inquires whether or not the SRQ line on the IEEE bus is currently being asserted SYNTAX SQ RESPONSE Y SRQ is being asserted N SRQ is not being asserted BUS STATES None EXAMPLES PRINT 1 SQ Issue SRQ CHECK command INPUT 1 SROSTAT Receive SRQ status TR TRIGGER The TRIGGER command issues a Group Execute Trigger GET bus command to the specified device If no address
13. ector and requires a standard DB 25P mating connector Refer to the following figure and table to understand the relationship of the Micro488 p connector s pins and the associated RS 232 signals Section 2 4 of this document includes wiring information for making your own cables 0000000000000 0000000000090 Micro488p Serial Connector Pinout The following table idetifies the above connector pins in regard to signal name and I O type 09 26 02 Getting Started Micro 488p Serial Connection RxD Accepts serial data sent by the RS 232 host Receive Data The signal level is low true TxD Transmits serial data to the RS 232 host Transmit Data The signal level is low true CTS The CTS input is used as a hardware handshake Clear To Send line to prevent the Micro488 p from transmitting serial data when the RS 232 host is not ready to accept it When RTS CTS handshake is selected the Micro488 p will not transmit data out TxD while this line is un asserted low If XON XOFF handshake is selected the CTS line is not tested to determine if it can transmit data RTS The RTS output is used as a hardware Request To Send handshake line to prevent the RS 232 host from transmitting serial data if the Micro488 p is not ready to accept it DSR This pin is used to provide power for the Data Set Ready Micro488 p if the DTR pin is in its false LOW state this pin must be in its true HIGH state in Gnd Ground order for t
14. er GET bus command to the specified device if no address is specified then GET affects those devices already in the listen state Enables or disables XON XOFF handshaking Temporarily inhibits serial transmission from the Micro488 p Restarts serial transmission from the Micro488 p 09 26 02 3 20 Appendix A Micro488 p Command Summary Appendix B ACG Addressed Command Group UCG Universal Command Group LAG Listen Address Group Character Codes and IEEE Multiline Messages TAG Talk Address Group SCG Secondary Command Group Appendix B Character Codes and IEEE Multiline Messages 09 27 02 Notes B 2 Appendix C Sample Initialization Program Sample Micro488 p initialization program Copyright 1992 IOtech Inc l This program demonstrates how to initialize the Micro488 p IEEE controller using Quick Basic This program will initialize the Micro488 P and establish IEEE communications CLS CLOSE Close all files this turns off DTR and DSR com COM1 19200 N 8 1 BIN leee0ut FREEFILE leeeln FREEFILE OPEN com FOR RANDOM AS IeeeOut Open the serial port on COM 1 t TIMER DO WHILE t 1 gt TIMER Wait for 1 Seconds LOOP FOR i 1 TO 5 Send 5 carriage returns with a l second delay seperation PRINT IeeeOut CHRS 13 t TIMER DO WHILE t 1 gt TIMER LOOP NEXT 1 PRINT IeeeOut I Send Init command PRINT IeeeOut EC 0 Turn off serial echo PRINT IeeeOut
15. ere In order to properly operate the Micro488 p the DTR and DSR lines on the COM port must be initialized first Usually this can be accomplished by closing and then opening the serial port Appendix C includes a Sample Initialization Program Once the DTR and DSR ines have been initialized the next step is to initialize the baud rate to be used with the Micro488 p This is done by sending the Micro488 p five carriage returns separated by a 0 1 second delay Now send the Micro488 p the following command J lt CR gt The Micro488 p should respond with the prompt gt character Now the IEEE488 bus is initialized and the Micro488 p ready for operation Programming the Micro488 p The next step involves writing a simple dumb terminal program to communicate with the Micro488 p The dumb terminal program is written in QuickBASIC for any IBM PC compatable computer and allows simple communication with IEEE 488 devices connected to the Micro488 p The first task is to open the serial port to which the Micro488 p is connected If the Micro488 p is connected to serial port 1 then the following line will open that serial port with the following parameters Baud Rate 19200 Parity NONE Data Bits 8 Stop Bits 2 OPEN COM1 19200 N 8 2 cs ds FOR RANDOM AS 1 Next wait a moment for the Micro488 p s power supply to stabilize t TIMER DO WHILE t 1 gt TIMER LOOP Getting Started 09 26 02 2 5 Now that the Micro488
16. he Micro488 p to operate properly DCD This pin sets the ground reference point for the other RS 232 inputs and outputs Data Carrier Detect The function of this pin is similar to the CTS pin This pin is tied internally to its true HIGH state DTR DataTerminal Ready Used to provide power for the Micro488 p when the DSR pin pin 6 is in its false LOW state Note that the DTR pin pin 20 must be in its true HIGH state in order for the Micro488 p to operate properly Getting Started 09 26 02 2 3 2 4 2 5 2 4 Serial Cable Wiring If a cable was not purchased with the interface the following diagrams will be helpful in making your own cable Simple soldering skills and attention to detail will ensure successful construction IBM PC XT PS2 to Micro488 p DB25 Female TXD RXD RTS CTS DSR GND DCD DTR d d d gt d DB25 Male TXD RXD RTS CTS DSR GND DCD DTR DB9 DCD RXD TXD DTR GND DSR RTS CTS IBM AT to Micro488 p Female DB25 Male 8 3 2 d d d Two Scenarios for Making an Interface Cable RS 232 Hardware Installation DCD RXD TXD DTR GND DSR RTS CTS Installation of the Micro488 p consists of plugging the device into an available serial port on the host computer 09 26 02 Getting Started 2 6 2 7 Is Anyone Out Th
17. interface clears the serial input pending commands and output pending data buffers and re initializes the internal IEEE controller hardware 09 26 02 Page 3 6 3 6 3 7 3 7 3 8 3 8 3 9 3 10 3 12 3 13 3 14 Command LOCAL LOCAL LOCKOUT OUTPUT REMOTE RESUME SERIAL POLL SERIAL TERMINATOR SRQ CHECK TRIGGER XOFF XON XOFF XON A 2 Code L addr LL O cmd O addr cmd RE addr RS SP addr TC n SQ TR addr X n lt CTRL gt S CHR 1 9 lt CTRL gt Q CHR 1 17 Description Without optional address instructs the Micro488 p to un assert the Remote Enable line causing devices on the bus to return to manual operation with optional address places bus device in the local mode by the Go To Local GTL bus command Instructs the Micro488 p to issue a Local Lockout IEEE bus command Sends data to the IEEE bus Asserts the Remote Enable REN bus management line Un asserts the Attention ATN bus signal removes the Micro488 p from the active controller state and allows transfers between two peripheral devices Performs a serial poll of the bus device specified responds with a number from 0 to 255 representing the decimal equivalent of the eight bit device response Sets the end of line terminators for input from the serial host Inquires whether or not the SRQ line on the IEEE bus is currently being asserted Issues a Group Execute Trigg
18. l 255 and OFF is invalid because F is not a valid decimal digit Note Bus addresses are the only exception to the numeric parameters rule Bus addresses both primary and secondary must be specified as two digit decimal numbers Hexadecimal bus addresses are not allowed 09 27 02 Command Descriptions 3 2 1 1 Bus Addressing The following conventions apply to bus addressing addr cmd CR LF 3 2 1 2 Terminators An IEEE bus address in the range from 00 through 30 An arbitrary command string which is sent to the particular IEEE device being addressed The carriage return character 13 amp HOD The line feed character 10 amp HOA The following conventions apply to terminators term EOI Command Descriptions Any single character specified as CR LF X as described previously part of terminator sequence used to mark the end of lines of data and commands The IEEE bus End Or Identify signal when asserted during the transfer of a character EOI signals that character as the last in the transfer On input EOI if specified causes the input to stop On output EOI causes the bus EOI signal to be asserted during transmission of the last character transferred 09 27 02 3 3 3 2 2 Response This portion of the command description describes the response that the user s program should read from the serial host s COM port after sending the command If a response is provided it must be read to mai
19. levels compliant with Federal Communications Commission rules Part 15 for Class A devices If necessary refer to the FCC booklet How To Identify and Resolve Radio TV Interference Problems stock 004 000 00345 4 which is available from the U S Government Printing Office Washington D C 20402 CE Notice Many IOtech products carry the CE marker indicating they comply with the safety and emissions standards of the European Community As applicable we ship these products with a Declaration of Conformity stating which specifications and operating conditions apply Warnings Cautions Notes and Tips Refer all service to qualified personnel This caution symbol warns of possible personal injury or equipment damage under noted conditions Follow all safety standards of professional practice and the recommendations in this manual Using this equipment in ways other than described in this manual can present serious safety hazards or cause equipment damage This ESD caution symbol urges proper handling of equipment or components sensitive to damage from electrostatic discharge Proper handling guidelines include the use of grounded anti static mats and wrist straps ESD protective bags and cartons and related procedures Specifications and Calibration Specifications are subject to change without notice Significant changes will be addressed in an addendum or revision to the manual As applicable IOtech calibrates its hardware to published s
20. ntain proper program segence 3 2 3 Bus States This portion of the command description describes the bus command and data transfers using IEEE bus mnemonics as listed in the following table Bus States 7 jes Is ATN Attention data Data Stins J J DCL DeviceClear 9 0 4 9 4 GET Group Execute Trigger x 0 o 1 o em emre Te IFC Interface Clear LAG Listen Address Group_ x 0 1 a d d r LLO LocallockOut x 0 o 1 o o Jo 1 MLA MyListen Address Xx 0 1 a a a r no MTA MyTalk Address Xx 1 0 a a ld Ir In REN Remote Enable SDC Selected Device Clear x 0 0 o o j1 jojo om ele eee e ela SPE Serial Poll Enable JA e eIn ejoo BS EL A DE RD TAG Talker Address Group x 1 0 a faja fr A en ES EHER ER ER ER EI CONT nee EEE ERZIEHER EN x don t care addrn IEEE bus address n EIER EE GEN Caka EDEA C PAE Lala oe 3 4 09 27 02 Command Descriptions If a command is preceded by an asterisk it is unasserted For example REN states that the remote enable line is unasserted REN without the asterisk states that the line is asserted 3 2 4 Examples This portion of the command description includes programming examples written in BASIC 3 3 The Commands Command descriptions relevant to Micro488 p now follow Command Descriptions 09 27 02 3 5 A The A command is a low level IEEE command which asserts
21. of data from device 16 even if it contains commas or other punctuation Command Descriptions 09 27 02 3 11 lt CTRL gt A ESCAPE The system command ESCAPE unlocks the Micro488 p from an inappropriate command such as a command requesting data from a nonexistent device When the ESCAPE command is received the serial handshake line RTS is un asserted It is asserted when the Micro488 p is capable of buffering commands If XON XOFF handshake is selected the software handshake state is not modified Issuing the ESCAPE command clears the serial input pending commands and causes the Micro488 p to wait for new commands SYNTAX lt CTRL gt A or CHR 1 RESPONSE None BUS STATES None EXAMPLE PRINT 1 CHRS 1 H HARDWARE HANDSHAKE The system command HARDWARE HANDSHAKE enables or disables hardware CTS RTS handshake SYNTAX H n n 0 disable hardware handshake n 1 enable hardware handshake RESPONSE None BUS STATES None EXAMPLE PRINT 1 H 1 Enable hardware handshake 3 12 09 27 02 Command Descriptions TB IEEE BUS TERMINATOR The IEEE BUS TERMINATOR command is used to select the IEEE bus terminator for reads from the IEEE bus The selected terminator signifies the end of an ENTER sequence The available terminators are 1 LF 2 CR 3 LF CR 4 CR LF SYNTAX TB n n is one of the available terminator types RESPONSE None BUS STATES None EXAMPLE PRINT HL TB yi Select LF as an IEEE bus terminator
22. p is powered on send it five carriage returns for the buad rate detection circuitry to set the internal baud rate Place a short time delay between the characters to ensure that the proper baud rate will be detected FORi 1TO5 PRINT 1 CHR 13 t TIMER DO WHILE t 2 gt TIMER LOOP NEXT i Next initialize the Micro488 p with the following command PRINT 1 I Now set up the Micro488 p with the following parameters Serial echo OFF Hardware Handshake ON XON XOFF handshaking OFF Serial terminator CARRIAGE RETURN IEEE bus terminator CARRIAGE RETURN LINE FEED PRINT 1 EC 0 PRINT 1 H 1 PRINT 1 X 0 PRINT 1 TC 2 PRINT 1 TB 4 After a short delay for command processing input any garbage characters that may be in the PC s serial input buffer t TIMER DO WHILE t 5 gt TIMER LOOP a INPUT LOC 1 1 2 6 09 26 02 Getting Started Now the Micro488 p is ready for operation Simply set up an infinite loop to check for user keypresses and to look for serial data in the PC s serial input buffer PRINT Ready DO IF LOC 1 THEN PRINT INPUT LOC 1 1 If anything is in the PC s serial input buffer print it to the screen k INKEY Get key press PRINT 1 k Send it to the Micro488 p PRINT k Echo keypress to screen LOOP The following is a complete listing of DUMBTERM BAS Micro488 p Dumb Terminal Program Copyright 1992 IOtech Inc CLS PRINT Initi
23. pecifications Periodic hardware calibration is not covered under the warranty and must be performed by qualified personnel as specified in this manual Improper calibration procedures may void the warranty Quality Notice IOtech has maintained ISO 9001 certification since 1996 Prior to shipment we thoroughly test ISO E u 9001 our products and review our documentation to assure the highest quality in all aspects In a spirit of continuous improvement IOtech welcomes your suggestions iij V Contents 1 Introduction 1 1 Description 1 1 1 2 Available Accessories 1 1 1 3 Specifications 1 2 1 4 Abbreviations 1 3 2 Getting Started 2 1 Inspection 2 1 2 2 Serial Coonfiguration 2 1 2 3 Serial Signal Descriptions 2 2 2 4 Serial Cable Wiring 2 4 2 5 Hardware Installation 2 4 2 6 Is Anyone Out There 2 5 2 7 Programming the Micro488 p 3 Command Descriptions 3 1 Introduction 3 1 3 2 Command Description Format 3 3 The Commands 3 5 Appendices A Micro488 p Command Summary B Character Codes and IEEE Multiline Messages C Sample Initialiazation Program Micro488 p Contents 09 26 02 vi 09 26 02 Micro488 p Introduction 1 1 Description The Micro488 p Bus Controller converts a host RS 232 computer into an IEEE 488 bus talker listener and controller It provides the basic IEEE 488 1978 bus implementa
24. the attention line After completion of this command the Micro488 p is left in the controller active state SYNTAX A RESPONSE None BUS STATES ATN EXAMPLE PRINTH1 A L The L command is a low level IEEE command which sends the LAG command to the specified device After completion of this command the Micro488 p is left in the controller active state SYNTAX L RESPONSE None BUS STATES ATN LAG EXAMPLE PRINT 1 L 10 Send LAG10 on the IEEE bus 3 6 09 27 02 Command Descriptions ML The ML command is a low level IEEE command which places the Micro488 p in the listen state After completion of this command the Micro488 p is ready to listen as soon as the RESUME RS command is issued SYNTAX ML RESPONSE None BUS STATES ATN EXAMPLE PRINT 1 ML IMT The MT command is a low level IEEE command which places the Micro488 p in the talk state After completion of this command the Micro488 p is ready to talk as soon as the RESUME RS command is issued SYNTAX MT RESPONSE None BUS STATES ATN UNT EXAMPLE PRINT 1 MT Command Descriptions 09 27 02 3 7 T The T command is a low level IEEE command which issues the talk command to the specified IEEE device SYNTAX T addr RESPONSE None BUS STATES ATN TAG EXAMPLE PRINT 1 T 10 Issue TAG to device 10 UL The UL command is a low level IEEE command which sends the UNL command to the IEEE bus This command instructs all devices on the IEEE bus to get
25. tion required for a system controller The Micro488 p may be located up to fifty feet from the host and may control as many as eight IEEE 488 bus instruments The Micro488 p interprets simple high level commands sent from the computer s serial port and performs the necessary and usually complex bus control and handshaking The commands and protocol are similar to those used by the Hewlett Packard HP 85 computer 1 2 Available Accessories Available accessories for the Micro488 p include CA 7 1 1 5 foot IEEE 488 Cable CA 7 2 6 foot IEEE 488 Cable CA 7 3 6 foot shielded IEEE 488 Cable CA 7 4 6 foot reverse entry IEEE 488 Cable CA 35 Cable Set includes one IBM PC XT PS2 to Micro488 p RS 232 Cable and one IBM AT to Micro488 p RS 232 Cable CN 20 Right Angle IEEE 488 adapter male and female CN 22 IEEE 488 Multi tap bus strip four female connectors in parallel CN 23 IEEE 488 panel mount feed through connector male and female ABC488 IEEE 488 ABC switch Micro488 p Introduction 09 26 02 1 1 1 3 Specifications IEEE 488 1978 Implementation C1 C2 C3 C4 and C28 controller subsets Terminators Selectable CR LF LF CR and CR LF with EOI Connector Standard IEEE 488 connector with metric studs Serial Interface EIA RS 232C AB BA BB CA CB Character Set Asynchronous bit serial Output Voltage 5 volts min RS 232C Input Voltage 3 volts min 15v max Baud Rate Selectable 300 1200 2400 4800 960
26. ult of an immediately preceding OUTPUT command SYNTAX O cmd unaddressed OA addr cmd addressed addr is a bus device address cmd is a string of characters to OUTPUT terminated by the serial terminator s RESPONSE None BUS STATES REN ATN cmd unaddressed ATN UNL UNT LAG GTL data addressed EXAMPLES PRINT 1 OA 22 ROCOT1X Send ROCOT1X to device 22 PRINT HL 2 Oe XYZ Send device 22 XYZ Command Descriptions 09 27 02 3 15 RE REMOTE The REMOTE command asserts the Remote Enable REN bus management line If the optional bus address is specified then REMOTE also addresses the device to listen placing it in the Remote addressed state SYNTAX RE addr RESPONSE None BUS STATES REN unaddressed REN ATN UNL UNT LAG addressed EXAMPLE PRINT 1 RE Assert Remote Enable RS RESUME The RESUME command un asserts the Attention ATN bus signal removing the Micro488 p from the active controller state and allowing transfers to take place between two peripheral devices SYNTAX RS RESPONSE None BUS STATES ATN EXAMPLE PRINT 1 RS Un assert ATTENTION line 3 16 09 27 02 Command Descriptions SP SERIAL POLL The SERIAL POLL command performs a Serial Poll of the bus device specified and responds with a number from 0 to 255 representing the decimal equivalent of the eight bit device response If rsv DIO7 decimal value 64 is set then that device is signaling that it requires service Serial Polls ar
Download Pdf Manuals
Related Search