Modicon Fiber Optic Repeaters User`s Guide
Contents
1. 0200eeee eee eeeeeees 14 1 10 Connecting the Repeater 0cc eee nn nananana 15 1 10 1 Observing Safety Precautions assau aunan enan 15 1 10 2 Rear Panel Connectors 2 cece eee eee eee 16 1 10 3 Connecting Power 0 00 na 17 1 10 4 Connecting the Network Cable 0 22 00 ee eens 17 1 10 5 Setting the Remote I O Shield to Chassis Jumper 18 1 10 6 Applying Power sssusa nen 18 1 11 Reading the Network Indicators 0 cece nn hanne 19 1 12 Troubleshooting cece eee eee nanna eens 20 1 12 1 Troubleshooting Fiber Repeaters for Modbus Plus 20 1 12 2 Testing Connections 0 nn 22 1 12 3 Troubleshooting Fiber Repeaters for Remote I O 24 1 12 4 Broken Cable Detection and Remedies 25 1 12 4 1 Remote I O Systems 0000 eee ee eee 25 1 12 4 2 Modbus Plus Networks 0 0eee eens 28 1 13 lt Specifications 2 eect sees cecal naa ala tes inves eens Lees ees 30 1 14 GIOSSAKY Sarianna enS mieki eae an ead eee ee 32 GM FIBR OPT Contents iii Figures Figure 1 Simplified Internal Schematic of Fiber Optic Repeaters 2 Figure 2 Example of Point to Point Connection 4 Figure 3 Example of Repeaters in a Bus Configuration 5 Figure 4 Example of Optical Star Configuration 6 Figure 5 Example of Self Healing Ring2. because of its higher available optical power E 490NRP253 FIBER OPTIC REPEATER 5 490NRP253 FIBER OPTIC 6 mee OPTICAL STAR COUPLER poron 490NRP254 FIBER OPTIC REPEATER 4 490NRP254 FIBER OPTIC REPEATER 1 490NRP253 FIBER OPTIC SEs REPEATER 2 490NRP253 FIBER OPTIC REPEATER 3 poron ex PLUS TAPS Compact 984 with MOT 201 U Compact 984 with MOT 202 Figure 4 Example of Optical Star Configuration 6 Fiber Optic Repeaters User s Guide REPEATER IBM PC AT IBM PC AT 16 BUTTON MMI OPERATOR PANEL COPPER CORE CABLE FIBER OPTIC CABLE GM FIBR OPT EO IBM PC AT Self Healing Ring Configuration In some cases because of the plant layout or network topology it may be desirable to connect the Modicon fiber optic repeaters in a self healing ring configuration To support this configuration the Repeaters have special features built into the signal timing that allow them to be connected in a ring The advantage of this approach is that if there is a break in the ring communications will continue on both legs of the cable thus adding a level of reliability to the system However it is important to note that there is no sense bit and detec
3. 10016 16 IN B805 00001 00016 16 0UT B804 When the PLC s Rx line is broken as depicted the SENS ed bit becomes 0 OFF The middle node output to coil 00097 is set to 0 OFF Coil 00097 controls normally open relays which when power is removed opens the circuits to coil 00001 and coil 00002 thus inhibiting these outputs As an alternative the logic could control a SKP block to prevent execution of that portion of the network which would ordinarily output data through coils 00001 and 00002 Refer to the Modicon 984 Programmable Controller Systems Manual GM 0984 SYS for further information about using STAT and SENS and SKP blocks for this application Be sure to test your logic for correct performance GM FIBR OPT Fiber Optic Repeaters User s Guide 27 Modbus Plus Networks Due to the nature of fiber optic cable it is possible to break or disconnect the TX line independent of the RX line The effect of this on a Modbus Plus network is shown in the following example PLC 1 Sain MODBUS PLUS CABLE PC3 Running MBPSTAT tt PLC 2 490 NRP 253 MODBUS PLUS PT to PT FIBER OPTIC CABLE WITH BROKEN OR DISCONNECTED TRANSMIT LINE y TX RX SA RX TX 490 NRP 253 MODBUS PLUS PT to PT PLC 4 S MODBUS PLUS CABLE PLC 5 Oa ee PC6 Running MBPSTAT SEE NETWORK STATUS DISPLAY A SEE NETWO
4. Modbus Plus Point to Point Bus and Line Drop Network Application Mounting Method Power Nominal Panel or Shelf Panel or Shelf 115 230 Vac 24 Vdc 115 230 Vac 24 Vdc NWFR85D200 Modbus Plus Bus and Line Drop 19 in Rack 125 24 Vdc 490NRP954 Remote I O Bus and Line Drop Panel or Shelf 115 230 Vac 24 Vdc NWFR89D200 Remote I O Bus and Line Drop 19 in Rack 125 24 Vdc Except for their operating power and mounting methods Modbus Plus repeater models 490NRP254 and NWFR85D200 are identical and Remote I O models 490NRP954 and NWFR89D200 are identical System Specifications Data Rate Modbus Plus Data Rate Remote I O Electrical Interface Optical Interface Pulse Width Distortion Jitter Bit Error Rate Wavelength Power Loss Budget includes 3dB of system Margin Maximum Distance for point to point connection Reliability Service Life MTBF 30 Fiber Optic Repeaters User s Guide 1 Mbit sec for Modbus Plus with Bi Phase S encoded data 1 544 Mbit sec for Remote I O with Manchester encoded data Modbus Plus connection via 9 pin D connector Remote I O via F Connector ST type Connectors lt 10 nsec 109 over specified Optical Receiver Dynamic Range 820 nm 50 125 um fiber 7 0 dB 62 5 125 um fiber 11 dB 100 140 um fiber 16 5 dB 2km over 50 um fiber O 3 5 dB km 3km over 62 5 um fiber 3 5 dB km 3km over 100 um fiber 5 dB km 5 years 50 000 hours minim
5. PANELMATE PLUS 1000 Figure 5 Example of Self Healing Ring Configuration GM FIBR OPT COPPER CORE CABLE FIBER OPTIC CABLE 984 785E CONTROLLER Fiber Optic Repeaters User s Guide 7 Selecting Fiber Optic Cable When selecting which type of fiber optic cable to use several factors must be considered among them the cable attenuation and the cable bandwidth Cable attenuation and bandwidth are parameters specified by the cable manufacturers and depend upon several factors 7 the wavelength and the spectral width of the optical signal 7 the cable index use graded index only and o the bandwidth depends upon the size of the cable 50 125 um 62 5 125 um and 100 140 um The maximum attenuation for an 820nm optical signal is 50 125 um cable 3 5 dB km 62 5 125 um cable 3 5 dB km 100 140 um cable 5 0 dB km The bandwidth is the parameter limited by the dispersion of the optical signal along the length of the cable Two types of dispersion exist modal dispersion and material dispersion The modal dispersion widely depends on the fiber core size numerical aperture NA and the difference in the refraction coefficient between core and cladding material of fiber optic cable This difference in refraction is called the cable index and results in a pulse spreading because of the different traveling distances for different rays of light entering the multimode fiber For example
6. PLUG POWER JUMPER CONNECTOR CONNECTOR AND FUSE CABLE RIO MODELS ONLY RIO MODELS ONLY MODBUS PLUS MODELS ONLY CONNECTOR DC DC MODELS GROUND FIBER PORT 1 FIBER PORT 2 00000 O i REMOTE I O REMOTE I O MODBUS PLUS SHIELD TO CHASSIS CABLE CABLE 125 VDC 24VDC JUMPER CONNECTOR CONNECTOR RIO MODELS ONLY RIO MODELS ONLY MODBUS PLUS MODELS ONLY Figure 8 Rear Panel Connectors 16 Fiber Optic Repeaters User s Guide GM FIBR OPT GM FIBR OPT Connecting Power Grounding The Repeater obtains its ground through the chassis ground screw or DC wire Connect the Repeater to the site ground After making and securing this connection use a continuity tester to verify the Repeater chassis is grounded to the site ground Connecting AC Power Before connecting power remove the power at its source The AC power cable supplied with the Repeater is keyed for North American 110 120 VAC power outlets If necessary install a different plug on the cable for the power source at your site Remove the AC power cable from the Repeater Set the power selector plug to the 110 120 VAC or 220 240 VAC position for the power source at your site To do this remove the power selector plug by prying under its tab using a small screwdriver Set the plug to the proper voltage position as shown on the plug body then reinsert it Insert the power cable into the rear panel connector Plug the cable into the AC
7. S908 is working properly it should cause the Remote I O indicator for FR1 to blink If that indicator blinks as expected then the fiber port indicator FP1 for FR2 should blink and the other FP2 should be OFF If the FP1 indicator does not blink check for proper connection Transmit to Receive Receive to Transmit If no results are obtained substitute a known good FR for the one at FR2 and proceed from the beginning If this fails the fault has been isolated to faulty fiber and fiber testing procedures must be used 24 Fiber Optic Repeaters User s Guide GM FIBR OPT Broken Cable Detection and Remedies Remote I O Systems Unlike S908 coaxial cable fiber optic cable contains physically separate transmit and receive lines It is possible to lose communications through the receive line while the transmit line remains intact as depicted here PLC 908 RI O COAXIAL CABLE TO DROP 2 490 NRP 954 S908 BRIDGE TX RX FIBER OPTIC CABLE WA lt BROKEN OR DISCONNECTED RECEIVE LINE RX TX 490 NRP 954 S908 BRIDGE 908 RI O COAXIAL CABLE TO DROP 2 908 B805 B804 RI O 16 IN 16 OUT HEAD A break in the receive line as shown above will deprive the PLC of input data Under ordinary circumstances the PLC will continue to drive outputs via the intact transmit line This could lead to outputs turning ON or OFF due to invalid INPUT STATE 0 input data A method t
8. This type of fiber provides high bandwidth capabilities link A fiber optic cable with connector attached to a transmitter source and receiver detector local area network abbr LAN A geographically limited communications network intended for the local transport of data video and voice 32 Fiber Optic Repeaters User s Guide GM FIBR OPT GM FIBR OPT mechanical splicing Joining two fibers together by mechanical means to enable a continuous signal Elastometric splicing is one example of mechanical splicing megahertz abbr MHz A unit of frequency that is equal to one million hertz micron abbr um Another term for micrometer One millionth of a meter 10exp 9meter mode A term used to describe a light path through a fiber as in multimode or single mode modulation Coding of information onto the carrier frequency This includes amplitude frequency or phase modulation techniques multimode fiber An optical waveguide in which light travels in multiple modes Typical core cladding sizes measured in microns are 50 125 62 5 125 and 100 140 nanometer abbr nm A unit of measurement equal to one billionth of a meter 10exp 9 meters numerical aperture The number that expresses the light gathering power of a fiber point to point A connection established between two specific locations as between two buildings repeater A device which consists of a transmitter and receiver or transceiver used to amplify a signa
9. for such troubleshooting are o a Modbus Plus node It can but need not be running an application All it must do is pass tokens to be usable o a length of Modbus Plus cable properly terminated o Fiber Optic Repeater o a fiber pigtail 7 knowledge and implementation of the above procedures The previous descriptions use the 490 NRP 253 Repeater which has a single fiber port You can use a two port Repeater in the same place as a single port unit but the reverse is not true When a two port unit is used as a point to point device one fiber port is simply not connected Fiber Optic Repeaters User s Guide 23 Troubleshooting Fiber Repeaters for Remote I O Examine this conceptual diagram of a typical Remote I O Fiber Optic application MASTER NODE PLC 5 0 mg 14 dB Ta K p To Other Coaxial Cable Drops or Repeaters Coax May or TX Fiber RX i May or May Not be i lt ED 490 NRP 954 a EBI 490 NRP 954 Ep3 May Not be Connected to FR1 FR2 Connected to Other Drops lt 7 Other Drops or Repeaters RX Fiber TX or Repeaters To Other 14 dB Tap Drops or Repeaters DROP O O00nc There are well documented procedures for analyzing the wireside characteristics of this type application and it is recommended they be used as a first line of attack and afterward whenever trouble is suspected If the
10. in the optical path must not exceed the specified Power Loss Budget for the chosen cable type The specified Power Loss Budget includes the loss of the two ST type connectors which connect at the two repeaters and also includes the system margin of 3 dB Thus only other components such as additional connectors star couplers and splices along with cable attenuation should be taken into account in calculating the loss Point to Point Example Point to Point connection of 3 km for two repeaters with one splice using 62 5 125 um optical cable with attenuation of 3 5 dB km Power Loss Budget in 62 5 125 um cable 11 dB Distance between Repeaters 3 km Cable attenuation 3 5 dB km Splice Loss 25 dB System loss 3 5 dB km x 3 km 25 dB 10 75 dB less than the allowable Loss Budget of 11 dB Star Coupler Connection Example Total end to end connection of 1 km for two repeaters through one star coupler using 100 140 um optical cable with attenuation of 5 dB km Power Loss Budget in 100 140 um cable 16 5 dB Kaptron 502402 4 4 x 4 100 140 um Star Coupler 8dB loss 2 ST type connectors 1 dB each Distance between Repeaters 1 km Cable attenuation 5 dB km System loss 5 dB km x 1 km 2x1dB 8dB 15 dB less than the allowable Loss Budget of 16 5 dB Fiber Optic Repeaters User s Guide 9 Calculating the Minimum Cable Distance Because the transmit optical power greatly depends of the fiber size the calculation of
11. join two fibers together to provide a means for attaching and decoupling it to a transmitter receiver or another fiber Commonly used connectors include the FC FCPC Biconic ST Connector Compatible D4 SMA 905 or 906 core The central region of an optical fiber through which light is transmitted decibel abbr dB Unit for measuring the relative strength of a signal digital A data format that uses two physical levels to transmit information A discrete or discontinuous signal dispersion The cause of bandwidth limitations in a fiber Dispersion causes a broadening of input pulses along the length of the fiber Three major types are a mode dispersion caused by differential optical path lengths in a multimode fiber b material dispersion caused by a differential delay of various wavelengths of lights in a waveguide material and c waveguide dispersion caused by light traveling in both the core and cladding materials in single mode fibers fiber A thin filament of glass An optical waveguide consisting of a core and a cladding which is capable of carrying information in the form of light fiber optics Light transmission through optical fibers for communication or signalling graded index Fiber design in which the refractive index of the core is lower toward the outside of the fiber core and increases toward the center of the core thus it bends the rays inward and allows them to travel faster in the lower index of refraction region
12. of nodes over the fiber optic medium The calculation of the number of chained Repeaters and the total distance of this type of fiber optic network is explained later in this guidebook PANELMATE PLUS 1000 984 785E COMPACT 984 984 685E A984 145 PROGRAMMABLE IBM PC AT PROGRAMMABLE with MOTION CONTROLLER CONTROLLER CONTROL MODBUS PLUS 490NRP253 FIBER OPTIC REPEATER TAPS 490NRP254 35 FIBER OPTIC REPEATER 490NRP254 FIBER OPTIC REPEATER i 6 6 e ams a sana 22 al 490NRP253 FIBER OPTIC REPEATER T COPPER CORE CABLE meen FIBER OPTIC CABLE Figure 3 Example of Repeaters in a Bus Configuration GM FIBR OPT Fiber Optic Repeaters User s Guide 5 IBM PC AT IBM PC AT MODBUS Optical Star Coupler Configuration The use of Optical Star Couplers active or passive can provide flexibility in the layout of Modbus Plus and Remote I O networks Figure 4 shows one example of an Optical Star Coupler configuration Additional repeaters can be connected in order to extend communication between electrical links If a passive Star Coupler is used the use of 100 140 um cable is recommended
13. other communications and or other control applications o Most 62 5 125 cables are rated at 3 5 dB loss per km With a multiconductor cable all the pairs come with an attenuation specification as measured 12 Fiber Optic Repeaters User s Guide GM FIBR OPT Mounting Shelf Panel Models Fiber Optic Repeater models are available for mounting on a horizontal shelf or vertical panel Your choice of mounting method should provide access to the Repeater for observing its status indicators You should also locate the unit for easy access to its rear panel connectors for ease of installation and future servicing The bottom surface of shelf panel models is fitted with pads for placement on a horizontal surface such as a shelf or platform For vertical mounting use the brackets supplied with the unit for bolting to a panel The brackets have tabs that insert into slots on the Repeater s bottom panel No additional hardware is required for securing the brackets to the Repeater You will have to furnish hardware for bolting the Repeater brackets to your panel Four bolts are required Typically standard 1 4 20 10mm bolts will be satisfactory The mounting brackets supplied with the unit for vertical panel mounting can also be used to secure the unit on a horizontal surface TOP VIEW ALLOW 4 0 IN 100 MM REAR CLEARANCE FOR ACCESS TO SWITCHES CABLES AND FUSE Fiber Optic Repeater 490NRP954 8 3 IN 211 MM 5 25 IN 1 5
14. the minimum distance is important to avoid overdriving the Repeater s optical receiver When 50 125 or 62 5 125 um cable is used there is no limit on the minimum distance required The minimum distance for other fiber sizes must be calculated Receiver Sensitivity 30 dBm Repeater Dynamic Range 20 dB meaning the maximum received Signal 10dBm Minimum _ Maximum Optical Power dBm Maximum Received Signal dBm Distance Cable attenuation dB km For example if 100 140 um fiber is used the maximum optical power is 4 dBm 4 dBm 10 dBm _42km 5 dB km i Conclusion When higher Optical Power is required when using the Optical Couplers or Splitters then it is permissible to use the larger size fiber For short distances and minimum distortions use of the 62 5 125 size fiber is a better solution Calculating the Number of Chained Repeaters Because the Repeaters are passive and do not regenerate the received optical data the number of chained repeaters is limited by the system s total pulse width jitter distortions The total allowable pulse width and jitter distortion is limited to 20 of the bit period or for Modbus Plus 200 nsec for Remote I O 130 nsec The Jitter contributed by Modicon s Fiber Optic Repeaters is 10 nsec per box The Jitter contributed by the Modbus Plus or Remote I O electrical interface is 40 nsec receive transmit The formula to determine the number N of chained Re
15. 3 IN 133 MM 39 4 _ 11 5 IN 292 MM gt t 12 83 IN 326 MM 14 08 IN 358 MM REAR PANEL VIEW 2 59 IN 66 MM Figure 6 Mounting Dimensions Shelf Panel Models GM FIBR OPT Fiber Optic Repeaters User s Guide 13 Mounting Rack Mount Models Fiber Optic Repeater models are available for installation into a standard 19 inch rack Your choice of mounting method should provide access to the Repeater for observing its status indicators You should also locate the unit for easy access to its rear panel connectors for ease of installation and future servicing You will have to furnish hardware for bolting the unit into your rack Four bolts are required When mounted the unit can support itself by its front mounting bolts It is light enough in weight that you do not have to provide rear support within the rack FRONT PANEL VIEW i 18 25 in 464 mm 19 0 in 483 mm TOP VIEW ALLOW 4 0 IN 100 MM REAR CLEARANCE FOR ACCESS TO SWITCHES CABLES AND FUSE 17 25 in 438 mm 3 9 15 in 232 mm 8 48 in 10 59 in 21 219 mm 269 mm 1 44in 37 mm Figure 7 Mounting Dimensions Rack Mount Models 14 Fiber Optic Repeaters User s Guide GM FIBR OPT Connecting the Repeater Observing Safety Precautions Before installing the Repeater read the warning and cautions below Follow them at all times during the installation of the Repeater Warning DO NOT view
16. Configuration 7 Figure 6 Mounting Dimensions Shelf Panel Models 13 Figure 7 Mounting Dimensions Rack Mount Models 14 Figure 8 Rear Panel Connectors 2 00cc cece eee teens 16 Figure 9 Indicators Layout 0 00 cece eee eee ee 19 iv Contents GM FIBR OPT Fiber Optic Repeaters User s Guide GM FIBR OPT 7 Introduction o Electrical Cable Connections o Fiber Optic Cable Connections o Selecting Fiber Optic Cable 7 Calculating the Optical Path o Recommended Materials o Mounting Methods 7 Installing the Repeater 7 Troubleshooting o Specifications Reading the Network Indicators Fiber Optic Repeaters User s Guide 1 Introduction This manual describes how to install and operate Modicon Fiber Optic Repeaters Part Numbers 490NRP253 490NRP254 490NRP954 NWFR85D200 and NWFR89D200 The repeaters have the following characteristics o Model 490NRP253 provides a Fiber Optic Point to Point link between two Modbus Plus connections The Repeater contains one Fiber Optic Transceiver and one electrical interface for Modbus Plus o Models 490NRP254 and NWFR85D200 provide Fiber Optic Bus and electrical Line Drop links between Modbus Plus nodes or network segments Each Repeater contains two Fiber Optic Transceivers and one electrical Modbus Plus interface o Models 490NRP954 and NWFR89D200 provide Fiber Optic Bus and electrical Line Drop links bet
17. Modicon Fiber Optic Repeaters User s Guide GM FIBR OPT Rev B Contents 1 1 INMFOCUCTION icsse Sees hee ota ema coe Neh pecan eee ewe Slee 2 1 2 Electrical Cable Connections 00ceeeeee eee eens 3 1 3 Fiber Optic Cable Connections 0 0eee ee nananana 3 1 4 Typical Cable System Layouts c cece eee eee eee 4 1 4 1 Point to Point Configuration oss soseen 4 1 4 2 Bus Configuration 0 ccc eee 5 1 4 3 Optical Star Coupler Configuration 0 000 eee 6 1 4 4 Self Healing Ring Configuration 22 002 ee eens 7 1 5 Selecting Fiber Optic Cable 0 ccc eee eee eee 8 1 6 Calculating the Optical Path ccc eee eee 9 1 6 1 The Optical Power Loss Budget 00eeeeeeee 9 1 6 1 1 Point to Point Example ssssoossnnnnnn 9 1 6 1 2 Star Coupler Connection Example 9 1 6 1 3 Calculating the Minimum Cable Distance 10 1 6 2 Calculating the Number of Chained Repeaters 10 1 7 Recommended Materials 00ece onn nn nannaa 11 1 7 1 COonnectokSssssvansetaa soma an tears tat astma His AEA 11 1 7 2 Termination KIIS erer eroan a Eka nen 11 1 7 3 Passive Coupler ne 11 1 7 4 TOOIS Pas es ene Sana a ten Seen oe cade woos Sa ites 12 1 7 5 Fiber Optic Cables soon oman 12 1 8 Mounting Shelf Panel Models 00eeeeeeeee eee eeaee 13 1 9 Mounting Rack Mount Models
18. RK STATUS DISPLAY B Note that the sample network consists of six nodes three on either side of each Fiber Optic Repeater A broken Tx line from the standpoint of nodes 1 2 and 3 will cause the Modbus Plus network indicator LED s on every node to illuminate This disconnect code consists of 2 flashes followed by a 2 second pause The two PLC s and the PC will cease data communications The MBPSTAT program running on the PC at node 3 displays all six nodes of the network but no communication activity 28 Fiber Optic Repeaters User s Guide GM FIBR OPT GM FIBR OPT MODBUS PLUS NETWORK STATUS version 2 30 Global Data Activity strike any key to exit Adapter 0 Success 0 Failure O DISPLAY A MODBUS PLUS NETWORK STATUS version 2 30 Global Data Activity strike any key to exit Adapter 0 Success 103 Failure 0 00 00 DISPLAY B Fiber Optic Repeaters User s Guide On the other side of the break nodes 4 5 and 6 re form into a smaller Modbus Plus network The Modbus Plus status LED s at each node blink rapidly indicating normal communication among these three nodes Note that MBPSTAT running on the PC at Node 6 displays only the three nodes of the re formed network 29 Specifications Product Identification The following table summarizes Fiber Optic Repeater part numbers and applications Part Number 490NRP253 490NRP254 Modbus Plus
19. a difference of 1 in refraction coefficient between core and cladding material for step index fiber produces a pulse spreading or pulse width distortion of 50 ns km Modal dispersion and the resultant pulse width distortion can be reduced by using a smaller core size cable using a graded index fiber and using a fiber with a smaller numerical aperture Material dispersion results in pulse spreading at the end of the fiber because of the difference in velocities for different wavelengths of the light signal and depends upon the wavelength and the spectral width of the transmit optical signal Shown below is the total amount of pulse width distortion or jitter contributed by fiber optic cable for different cable sizes for 820 nm with 50 nm of spectral width optical signal 50 125 um 3ns km where X is the jitter 62 5 125 um 5ns km X in nanoseconds 100 140 um 7 5ns km per kilometer gt Note The value of X is used in the formulas on Page 18 when calculating the maximum number of chained repeaters 8 Fiber Optic Repeaters User s Guide GM FIBR OPT GM FIBR OPT Calculating the Optical Path The Optical Power Loss Budget The maximum length of any optical path between two fiber optic repeaters must be calculated separately and depends on the total loss in all components used in the path including fiber optic cable optical connectors star couplers and splices The sum of the losses in all components used
20. g packets from another fiber optic repeater Modbus Plus ON steady amber when the repeater is receiving packets from devices on the wireside Modbus Plus network The Modbus Plus indicator is also activated by receive signals illustrated conceptually as RX lt lt Optical Signal f Modbus Plus Packet 20 Fiber Optic Repeaters User s Guide GM FIBR OPT The following example makes use of this information in bringing up two point to point fiber optic repeaters Connect the repeaters as shown 490NRP253 FIBER OPTIC REPEATER FR1 490NRP253 FIBER RX TX OPTIC REPEATER FR2 POWER lt POWER NOTE Connect Transmitter to Receiver and Receiver to Transmitter Duplex cables have markings on one of the two jackets to aid in identification Apply power and observe 490NRP253 FIBER TX RX 490NRP253 FIBER OPTIC REPEATER FR1 OPTIC REPEATER FR2 RX TX X o o y o o Pwr FP MB Pwr FP MB Both power lights should illuminate no other lights should come on Now connect a single Modbus Plus Node to one of the repeaters 490NRP253 FIBER TX RX 490NRP253 FIBER OPTIC REPEATER FR1 OPTIC REPEATER FR2 MODBUS PLUS NODE 1 3 RX TX y o x y x o Pwr FP MB Pwr FP MB The Modbus Plus Node generates packets regardless of whether an application is present therefore the Modbus Plus receiver is getting data and its indicator is blinking The transmitter of FR1 passes the pac
21. is ground o When the jumper is in the 1 position the RIO cable shield is isolated from chassis ground by a capacitor Applying Power Before applying power verify that all power connections electrical cable connections and fiber optic connections are correctly installed for your application Applying AC Power If you are using AC line power apply AC to the Repeater site The Repeater s main power switch controls the power to the unit Set the power switch to the 1 position ON The units POWER OK indicator will illuminate Applying DC Power If you are using DC power switch on your DC to the Repeater The unit s POWER OK indicator will illuminate 18 Fiber Optic Repeaters User s Guide GM FIBR OPT GM FIBR OPT Reading the Network Indicators The layout of the Repeater s indicators is shown in Figure 9 Refer to the illustration applicable to your unit 490 NRP 253 O O O power OK fiber port modbus plus 490 NRP 254 O o o O power OK fiber port 1 fiber port 2 modbus plus FR85D200 O O o o modbus plus fiber port 2 fiber port 1 power OK 490 NRP 954 o o O O power OK fiber port 1 fiber port 2 remote I O FR89D200 O O e remote I O fiber port 2 fiber port 1 power OK Figure 9 Indicators Layout The POWER OK indicator illuminates steadily when the Repeater has normal power from the AC line or DC source and its internal power supply is operating normally The MODBUS PLUS or REMOTE I O port indicato
22. ith MOTION CONTROL A Typical Cable System Layouts This section of your manual describes four typical configurations and is illustrative of the wide range of Fiber Optic Repeater applications Point to Point Configuration Figure 2 shows a Point to Point connection for two segments of a Modbus Plus network using Fiber Optic Repeaters The distance between the two Repeaters is limited by the maximum allowable power loss from end to end Power loss includes the fiber optic cable attenuation connector losses at the Fiber Optic Receiver and Transmitter ports and the system margin of 3 dB Methods of calculating the power loss are explained later in this guidebook IBM PC AT 490NRP253 FIBER OPTIC REPEATER 490NRP253 FIBER OPTIC REPEATER MODBUS PLUS TAPS 984 685E PROGRAMMABLE CONTROLLER o a COPPER CORE CABLE menn FIBER OPTIC CABLE Figure 2 Example of Point to Point Connection 4 Fiber Optic Repeaters User s Guide GM FIBR OPT Bus Configuration Figure 3 shows the use of Fiber Optic Repeaters in a Bus configuration This type of configuration permits chaining multiple Repeaters to extend the fiber optic link thus increasing the distance between the nodes of the network Such a configuration permits connection of single nodes or clusters
23. kets to the receiver of FR2 and its fiber port indicator will blink gt Note The Repeater s blinking pattern does not follow the standard Modbus Plus network indicator flashing pattern of other Modbus Plus devices GM FIBR OPT Fiber Optic Repeaters User s Guide 21 To verify proper operation of the rest of the system relocate Modbus Plus Node 1 so it is attached to FR2 as shown below If the system is configured correctly the indicators should illuminate as follows Repeater Indicator Fiber Port Modbus Plus FR1 BLINKING OFF FR2 OFF BLINKING TX RX 490NRP253 FIBER 490NRP253 FIBER OPTIC REPEATER FR1 OPTIC REPEATER FR2 MODBUS PLUS RX TX NODE 1 mM HK o M gt 3K Pwr FP MB Pwr FP MB Testing Connections Most failures in any kind of network are in the medium that is the wire the fiber and their connections Therefore if any of the above configurations fail to give the expected state of the indicators your first suspicion should be that the cable fiber or their terminations are at fault Test 1 In the above example with Node 1 alone attached to FR1 if the Modbus Plus light on FR1 does not blink check for continuity of the Modbus Plus cable pin to pin If this is correct try attaching Node 1 to FR2 If the Modbus Plus indicator on FR2 begins to blink then Node 1 must be transmitting FR2 is receiving and FR1 has failed and needs replacement If Node 1 attached to FR2 fails t
24. l to increase the system length receiver An electronic package which converts optical signals to electrical signals scattering A property of glass which causes light to deflect from the fiber and contributes to losses source The means used to convert an electrical information carrying signal to a corresponding optical signal for transmission by fiber the source is usually a Light Emitting Diode LED or Laser splicing The permanent joining of fiber ends to identical or similar fibers without the use of a connector See also fusion splicing and mechanical splicing star coupler Optical component which allows emulation of a bus topology in fiber optic systems step index fiber Optical fiber which has an abrupt step change in its reflective index due to a core and cladding that have different indices or refraction Typically used for single mode transmitter An electronic package which converts an electrical signal to an optical signal wavelength The distance between the same point on adjacent waves Fiber Optic Repeaters User s Guide 33
25. nclosure use AMP Model 502402 4 a 19 Rack Mount Enclosure 1 7 high GM FIBR OPT Fiber Optic Repeaters User s Guide 11 Tools Table 3 Tools Product Part Number Description Use 3M Photodyne Optical Source Driver 9XT Hand held optical source driver requires a light source 3M Photodyne Optical Light Source 1700 0850 T 850 nm Light Source ST Connectors for 9XT 3M Photodyne Power Meter 17XTA 2041 Hand held Fiber Optic Power Meter 3M Optical Light Source 660 nm visible 7XE 0660 J Use with 9XT to troubleshoot raw fiber requires FC ST patch cord 3M FC ST Patch Cord BANAV FS 0001 Connects FC connector on 7XE to ST 3M Bare Fiber Adapter ST Compatible 8194 Permits use of above source and meter to test raw fiber 2 required Fiber Optic Cables Modicon recommends the use of 62 5 125 graded index multimode glass fiber for all applications except where the use of a passive coupler requires use of 100 140 fiber for sufficient launch power to get a satisfactory signal budget Many cable vendors offer multiple choices for a variety of code ratings o From the variety of cables offered by AMP or Belden select the one that meets the demands of your application Wherever possible Modicon recommends that a multiconductor cable be considered since it is inexpensive it provides a backup in case a cable gets cut in the process of pulling it and you will always find uses for the extra path s be it for voice video
26. o cause the Modbus Plus indicator to blink Node 1 must be presumed to have failed Test 2 Assuming Node 1 attached to FR1 succeeds in illuminating the Modbus Plus indicator the FP indicator of FR2 should blink If it does not reverse the fiber connections at either one or another but not both of the fiber repeaters The correct connection is Transmitter to Receiver Receiver to Transmitter If the fiber port indicator of FR2 still fails to blink reattach Node 1 to FR2 Test 3 After Node 1 is reattached to FR2 the Modbus Plus indicator of FR2 and the FP indicator on FR1 should both be on If this test succeeds you have probably isolated the failure to the optical fiber now connected to the receiver of FR2 the transmitter of FR1 To confirm this suspicion reverse the fiber connections to both FRs If as suspected one fiber repeater is bad Node 1 attached to FR2 will no longer communicate to FR1 If Node 1 is reattached to FR1 then the signal will transmit to FR2 Having isolated the fault to the fiber you will have to use other tools such as a light source and power meter to verify discontinuity and then confirm continuity after correction of the fault 22 Fiber Optic Repeaters User s Guide GM FIBR OPT GM FIBR OPT Using the tests just described most of the time you will be able to find the fault failure in a broken system without use of elaborate test equipment Necessary components pre tested for reliability
27. o prevent this from happening is to use STAT and SENS function blocks in the PLC s ladder logic to detect the loss of input communication This logic can inhibit outputs from improper state changes Here is an example GM FIBR OPT Fiber Optic Repeaters User s Guide 25 Seg 1 41 1 00097 00001 pj 00097 00002 The STAT and SENS blocks monitor the I O status of Drop 2 and inhibit outputs 00001 and 00002 if communications are lost The STAT block provides access to the system s status including the status of S908 communications The status information is stored in a table which starts at 40101 and has a length of 187 words as shown in the top and bottom nodes of the STAT block The SENS block has been programmed to sense the first or Communications Health bit SENS top node value 1 of the 185th word in the status table SENS middle node value 40285 This bit is the communications health for Drop 2 of the S908 Coils 00001 and 00002 in the example have been configured as outputs in the I O Map as shown below 26 Fiber Optic Repeaters User s Guide GM FIBR OPT Utility DelDrop HoldTme ASCPort GetDrop Quit F4 _F2 ___F3 ___F4___F___F6 _F 7 Le v8 F8 OF F _F9 I O MAP 800 SERIES I O Drop i 2 of32 Rack 1 Drop Hold Up Time 3 x100ms ASCII Port Number Inputs 16 Number Outputs 16 Module Reference Numbers Module Type Input Output Description 984 PLC 685E 984 PLC 685E 10001
28. peater has the same network connections specifications and restrictions as other Modbus Plus or Remote I O devices and must be treated accordingly Refer to the Modbus Plus System Planning and Installation Guide GM MBPL 001 or the 984 Remote I O Planning Guide GM 0984 RIO for information regarding planning your network configuration and the installation of the network electrical cable Fiber Optic Cable Connections The fiber optic cable is connected to the fiber optic ports by a low loss industrial ST type connector All of the repeaters are passive meaning there is no regeneration of the received signal in the repeater and no additional delay to the signal produced by the repeater Prior to installing the Fiber Optic Repeaters fiber optic cable must be installed Follow the cable manufacturer s recommendations for routing installation and testing of the cable Take care when terminating the ends of each fiber optic cable in order to minimize loss of the optical signal Follow the manufacturer s guidelines for installing optical connectors Test the cable for proper attenuation prior to the connection of the Fiber Optic Repeaters The cable ends should be accessible at each installation site Allow sufficient cable length for a service loop and strain reliefs Label each cable end to facilitate future maintenance Fiber Optic Repeaters User s Guide 3 BM85 BRIDGE MULTIPLEXER COMPACT 984 A984 145 w
29. peaters is N 200 nsec X L nsec 40 nsec For Modbus Plus 10 nsec where L is the total cable length km and X is the jitter in ns km see Page 16 N 130 nsec X L nsec 40 nsec For Remote I O 10 nsec where L is the total cable length km and X is the jitter in ns km see Page 16 10 Fiber Optic Repeaters User s Guide GM FIBR OPT Recommended Materials Modicon offers these guidelines for selecting optical materials Connectors Table 1 Suggested Connectors Connector Type Part Number Description St Bayonet 3M 6105 Epoxy 40 to 80 C Operational temp St Bayonet 3M 6100 Hot Melt 40 to 60 C Push Pull St 3M 6102 Epoxy 40 to 80 C ST Bayonet AMP 501380 Series Epoxy 30 to 70 C ST Cleave and Crimp AMP 504034 Series Cleave and Crimp 40 to 65 C Mechanical Line Splice 3M 2529 Fiberlok II One size fits all 40 to 80 Termination Kits Table 2 Suggested Termination Kits Kit Type Part Number Description Bayonet or Push Pull ST 3M 8154 Epoxy 110 or 220 VAC only for 3M Connectors Bayonet or Push Pull ST 3M 6150 Hot Melt 110 or 220 VAC only 3M Bayonet ST AMP 501258 7 Epoxy 110 VAC only AMP Connectors Bayonet ST AMP 501258 8 EPOXY 220 VAC only AMP Mechanical Line Splice 3M 2530 Fiber Splice Prep Kit Complete with Cleaving Tool Passive Coupler The AMP Model 95010 4 is a pig tail option and must be used with an e
30. power source Connecting DC Power Before connecting power remove the power at its source Connect the source to the DC power terminals observing the proper polarity Connecting the Network Cable The electrical cable should already be run to the Repeater site with a connector installed If the cable and connector are not in place refer to the Modbus Plus System Planning and Installation Guide GM MBPL 001 or the 984 Remote I O Planning Guide GM 0984 RIO for information regarding planning your network configuration and the installation of the network electrical cable The fiber optic cables should already be run to the site with connectors installed If they are not in place install them using the guidelines given earlier in this guide Each cable should be labeled to identify the transmit receive link to which it connects Refer to Figure 8 Connect the Modbus Plus or Remote I O electrical cable and the fiber optic cables to the Repeater s rear panel connectors Secure the electrical cable connector by tightening its two screws Fiber Optic Repeaters User s Guide 17 Setting the Remote I O Shield to Chassis Jumper The RIO cable shield to chassis jumper on the rear of the unit is shipped in the neutral position midway between 1 and 2 pins Set the jumper to the position that will be used in your application o When the jumper is in the 2 position the RIO cable shield is connected directly to chass
31. r lights when a signal is received at the Repeater s electrical port Each FIBER port indicator lights when a signal is received at the fiber RX port If a port indicator fails to illuminate it can indicate a lack of transmitted signal at another network node Before replacing the Repeater check the cable connections on the rear panel for a possible incorrect or loose connection Also check the indicators on other devices on the signal path to see if the signal loss is external to the Repeater Fiber Optic Repeaters User s Guide 19 Troubleshooting Troubleshooting Fiber Repeaters for Modbus Plus The indicator lights on Modicon s Modbus Plus Fiber Optic Repeaters can be used to debug and troubleshoot an application In fact when the function of the indicators is understood an installer can usually successfully bring on line good equipment and isolate fault down to the replaceable element of a system having faulty components This requires only a knowledge of the indicators operation and the use of known good components This section explains how the indicators work and how such knowledge can be used by an installer to bring up a system or in case of fault how to troubleshoot down to the replaceable component An example of indicators on a Modbus Plus Repeater is shown below power OK fiber port modbus plus Power Fiber port 1 ON steady green when power is applied ON steady amber when the fiber receiver is receivin
32. s high into open circuit Surge Transients Electrostatic Discharge 2 kV IEC 801 5 level 3 8 kV ten discharges IEC 801 2 level 3 Fiber Optic Repeaters User s Guide 31 Glossary attenuation The decrease in magnitude of power of a signal in transmission between points A term used for expressing the total losses on an optical fiber consisting of the ratio of light output to light input Attenuation is usually measured in decibels per kilometer dB km at a specific wavelength The lower the number the better the fiber Typical multimode wavelengths are 850 and 1300 nanometers nm single mode at 1300 and 1550 nm NOTE When specifying attenuation it is important to note if it is nominal or average room temperature value or maximum over operating range bandwidth A measure of the information carrying capacity of an optical fiber normalized to a unit of mHz km Fiber bandwidth depends on the length of the fiber and is usually expressed in mHz km even though the length dependence is not linear for multimode fibers bit period The time required to define a data bit at a particular bit rate For Modbus Plus 1 mBit results in 1 Bit Rate 1 1 x 106 106 1 msec For Remote I O 1 1 544 x 106 648 usec 648 nsec cladding The material surrounding the core of an optical waveguide The cladding must have a lower index of refraction in order to steer the light in the core connector A mechanical device used to align and
33. the ends of fiber optic cable under magnification while a transmit signal is present on the cable SEVERE EYE DAMAGE MAY RESULT Use white light ONLY A Caution If you are replacing a Repeater on an active Modbus Plus network the communication between the two links of the network will be temporarily disabled as you replace the unit Always plan for an orderly shutdown of your control process if necessary while you replace a Repeater on an active network A Caution Fiber Optic Repeaters CANNOT be operated with both 115 VAC and 24 VDC power applied at the same time i e as with UPS backup or with both 125 VDC and 24 VDC applied at the same time A Caution When DC power is used the POWER switch on the unit is disabled Power is supplied to the unit when source power is activated Under DC power the unit does not provide surge protection A Caution Do not remove the fiber optic connector covers until the fiber cable is about to be connected Also if any optical connector will remain unused do not remove the connector covers from the unused connector After connecting the fiber cable retain the dust covers for future use GM FIBR OPT Fiber Optic Repeaters User s Guide 15 Rear Panel Connectors AC DC MODELS 24 VDC CHASSIS FIBER PORT 1 FIBER PORT 2 CONNECTOR GROUND SCREW POWER POWER REMOTE I O REMOTE I O MODBUS PLUS SELECTOR SWITCH SHIELD TO CHASSIS CABLE CABLE
34. tion of a fault is only accomplished through visual inspection of the indicator lights on each Repeater and by inspecting the physical status of the cable If fault tolerance with diagnostics is required from the network the recommended approach is to use dual cable Modbus Plus Communication Adapters such as the AM S985 800 which do have health and status bits associated with each leg of the cable Figure 5 shows the Self Healing Ring configuration of Modbus Plus or Remote I O links connected by Fiber Optic Repeaters over the optical medium This configuration can be achieved by connecting the second transceiver of the first and last Repeater in order to close the optical loop This type of connection has all the advantages of the previously described configurations along with built in redundancy A broken connection between any two Repeaters in the ring will automatically reconfigure the network to continue the communication The total length of the fiber optic cable in this case can be up to 10 km 32 000 ft and is essentially limited by the blanking built into the Repeater to prevent the second pass of the data through the optical loop 984 685E CONTROLLER IBM PC AT 490NRP254 490NRP254 490NRP254 FIBER OPTIC FIBER OPTIC FIBER OPTIC REPEATER REPEATER REPEATER 490NRP254 490NRP254 490NRP254 FIBER OPTIC FIBER OPTIC FIBER OPTIC REPEATER REPEATER REPEATER
35. um 30 C assuming fixed ground and component stress within maximum specifications GM FIBR OPT GM FIBR OPT Power Reguirements AC DC AC Input 90 130 VAC 180 264 VAC DC Input 19 2 30 VDC AC Internal Fuse Rating Power Requirements DC DC DC Input 105 140 VDC 19 2 30 VDC Retention on Power Loss Inrush Current Ground Leakage Models 120 mA 60 mA 300 mA 1A 110V 5 A 220 V Models 41 mA 125 VDC 300 mA Remains in regulation gt 10 ms after removal of power 6 A typical 125 VDC 1 mA 140 VDC Optical Transmitter Specification Optical Power Measured with 1m Test fiber Rise Fall Time Silence or OFF Leakage 13 0 20 0dBm average power in 50 125 um Fiber cable 10 0 16dBm average power in 62 5 125 um Fiber cable 4 0 10 5dBm average power in 100 140 um Fiber cable 20 nsec or better 43 dBm Optical Receiver Specification Receiver Sensitivity Dynamic Range Directed Silence Environmental Specification Operating Temperature Storage Temperature Humidity Radiated Susceptibility Surge Withstand Fast Transient 30dB m average power 20 dB 36 dB 0 to 60 C 40 to 85 C 10 95 non condensing 27 500 mHz 10 V m IEC 801 3 level 3 2 kV 1 kV on I O IEC 801 4 level 3 Surge Withstand Oscillatory Wave 2 5 kV IEEE 472 Surge Withstand tests into 50 ohms using V 3300 Generator corresponds to levels twice a
36. ween Remote I O nodes or network segments Each Repeater contains two Fiber Optic Transceivers and one electrical Remote I O interface Application Mounting Method Power Nominal Part Number 490NRP253 Modbus Plus Point to Point Panel or Shelf 115 230 Vac 24 Vdc 490NRP254 Modbus Plus Bus and Line Drop Panel or Shelf 115 230 Vac 24 Vdc NWFR85D200 Modbus Plus Bus and Line Drop 19 in Rack 125 24 Vdc 490NRP954 Remote I O Bus and Line Drop Panel or Shelf 115 230 Vac 24 Vdc NWFR89D200 Remote I O Bus and Line Drop 19 in Rack 125 24 Vdc Except for their operating power and mounting methods Modbus Plus repeater models 490NRP254 and NWFR85D200 are identical and Remote I O models 490NRP954 and NWFR89D200 are identical POWER OK EXTERNAL POWER MBUS RIO CONNECTIONS SUPPLY ELECTRICAL RX TP a ELECTRICAL TX ELECTRICAL PORT FIBER CH1 RX FIBER OPTIC CHANNEL 1 FIBER CH1 FIBER CH1 TX E C COMMUNICATION CONTROLLER FIBER CH2 RX FIBER OPTIC FIBER CH2 TX CHANNEL 2 FIBER CH2 INTERFACE Figure 1 Simplified Internal Schematic of Fiber Optic Repeaters 2 Fiber Optic Repeaters User s Guide GM FIBR OPT GM FIBR OPT Electrical Cable Connections Electrical connection to the Modbus Plus network is through the standard Modbus Plus 9 pin D connector Connection to the Remote I O network is through an F style connector and external Modicon Remote I O 14 db tap The electrical port of the Re
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