Black Box Modem Fiber Optic Modem User's Manual
Contents
1. Black Box Corporation 1000 Park Drive Lawrence PA 15055 1018 Tech Support and Ordering 724 746 5500 Fax 724 746 0746 To contact us about Black Box products or services info blackbox com Baud Rate RS 232 RS 422 485 Operation Operation 460 8 kbps N A 2 Model Number MED100A 230 4 kbps N A 4 Description DIN mount Fiber Optic Converter 115 2 kbps 2 8 Type Light industrial ITE equipment 57 6 kbps 8 16 Application of Council Directive 89 336 EEC C 38 4 kbps 16 24 Standards EN A E 19 2 kbps EA AB cd A od A pee a and lower 32 32 EN 61000 4 2 4 3 4 4 4 5 4 6 4 8 4 11 MED100A 304 pg 4 4 6132 r1 Table 4 Operating Parameters Parameter Min Typical Max Conditions Data Rates RS 232 Operation 0 bps 115 2 kbps Data Rates RS 422 485 Operation 0 bps 500 kbps Power Supply Voltage 10VDC j12VDC 30VDC Power Supply Current Draw 140 mA Full RS 485 Termination Optic Wavelength 820 nm Fiber TX Launch P ower 17 dBm 13dBm_ 10 dBm Minimum Required Fiber Rx Power 25 4 dBm 24 dBm Maximum Receiver Power 10 dBm Coupled P ower Budget 12 1 dB Fiber Range 2 5 miles End to End Delay 2000ns_ 2650 ns Point to Point RS 232 Operation See Notes 1 amp 2 End to End Delay 550 ns 1000 ns Point to Point RS 422 485 Operation See Notes 1 amp 2 End to End Skew 900 ns 1100 ns Point to Point RS 232 Operation See Note 3 End to2. TOON 485 2 Wire Device MED100A eet Dan T L e Li i TORT ORDE 1 RD A 1 1G TDA 1 Li Li 1 O RDB TH TDB GND i 1 M i I Li I Li Black Box Corporation 1000 Park Drive Lawrence PA 15055 1018 Tech Support and Ordering 724 746 5500 Fax 724 746 0746 To contact us about Black Box products or services info blackbox com MED100A 304 pg 2 4 6132 1 Fiber Optic Connections The MED100A uses a separate LED emitter and photo detector operating at 820 nm wavelength Connections to the emitter and detector are on ST type connectors Most multimode glass fiber size can be used including 50 125 um 62 5 125 um 100 140 um and 200 um One fiber is required for each connection between a transmitter and receiver Ina point to point configuration two fibers are required between the two modems one for data in each direction A multi drop ring configuration requires one fiber between TX and RX around the loop See Figure 2 for typical point to point and multi drop configurations The most important consideration in planning the fiber optic link is the power budget of the fiber modem This value represents the amount of loss in dB that can be present in the link between the two modems before the units fail to perform properly This value includes line attenuation as well as connector loss For the MED100A the typical connector to connector power budget is 12 1 dB Because 62 5 125 um cable typically has a line attenuation of 3 dB
3. End Skew 50 ns 120 ns Point to Point RS 422 485 Operation See Note 3 Maximum Total Fiber Ring Length 5 Miles See Note 1 Delay between Rx amp Tx ona fiber ring 52 us See Note 4 Note 1 For the total transmission time over long fibers RS 232 DATA IN he time to transverse the fiber must be considered if delay is an issue Light takes about 8 05 microseconds to travel over 1 mile of fiber Note 2 When operating in a ring configuration each node in addition to the two in the point to point specification adds an additional 100 to 200 nanoseconds of delay Note 3 When operating in a ring configuration each node in addition to the two in the point to point specification adds an additional 50 to 70 nanoseconds of skew Note 4 When operating in a ring configuration each serial device must wait at least this minimum time between receiving data from the ring and transmitting back on to it 6 DO RS 232 DATA OUT AO GND B Cc M R8 4 7K Gom oles SW1 7 HO Q Koma if l a Ca 422088 RD B Rt a7 o L O Rt6 eno 9 o 53 47K SW1 8 DUPLEX R17 10K f SWITCH 7 ON 485 OFF 422 J SWITCH 8 ON HD OFF FD 10 TO 30 VDC IN POWER CIRCUIT R2 3 4 0W TH 75 i O le TRANSMITTER ST CONNECTOR 6 a R3 1 470 2 RS 422 485 2 lt 3 o hAl c6 4 TIMING CONTROL Ah A L DETECTOR m BLOCK T ST CONNECTOR BAUD RATE JPA Wi o gt 57 6K 4 p1 384K 2 192K 5 c9 9600 4 i 01 4800 5 Figure 4 MED100A C
4. MED100A 304 pg 1 4 6132 1 Model MED100A Fiber Optic Modem Sends RS 232 422 485 Signals Up to 2 5 Miles CE seseo Model MED100A Fibor Drivor AS48508 232 to rer i Description The MED100A is designed to provide the most versatile connection possible between any asynchronous serial equipment using Fiber Optic cable It allows any two pieces of asynchronous serial equipment to communicate full or half duplex over two fibers at typical distances up to 2 5 miles The converter can also be set up in Repeater mode to create a multi drop master slave configuration allowing one serial device to talk to multiple slave devices around a fiber ring The DIN rail mountable box makes it ideal for industrial cabinets and enclosures RS 232 data signals up to 115 2K bps and RS 422 or RS 485 data signals up to 460K bps are supported Different standards can be mixed and matched to allow RS 232 devices to connect to your RS 422 or RS 485 system This means the MED100A can replace converters and isolators when connecting remote devices while providing the EMI RFI and transient immunity of optical fiber The MED100A supports both the Transmit and Receive data lines and provides full hardware control of the RS 422 485 driver with automatic Send Data Control circuit Timeouts are dip switch selectable between 0 10 and 2 2 ms All serial connections are provided on terminal blocks while the multimode fiber is connected via two ST connectors The u
5. ircuit Diagram Black Box Corporation 1000 Park Drive Lawrence PA 15055 1018 Tech Support and Ordering 724 746 5500 Fax 724 746 0746 To contact us about Black Box products or services info blackbox com
6. nit is powered by 10 to 30VDC at 140 mA max RS 232 Connections Connection of the MED100A is simple and straightforward The RS 232 driver and receiver are connected to 2 terminal blocks The RS 232 DATA OUT is on terminal block A and the RS 232 DATA IN is on terminal block D Ground is located on terminal block B and C and power comes in on terminal block F RS 422 and RS 485 Connections The RS 422 485 driver and receiver are connected to 4 terminal blocks Signal ground is on terminal block M and power comes in on terminal block J When connecting to a four wire RS 422 485 device or system connect the output of your device to terminal block L RDB or RD and terminal block K RDA or RD Connect the input to your device to terminal block H TDB or TD and terminal block G TDA or TD For two wire RS 485 systems the driver and receiver of the MED100A must be connected together by tying terminal blocks L and H together and G and K together This allows the MED100A to communicate half duplex over the same pair Refer to Figure 1 for connection diagrams to your RS 422 or RS 485 equipment If termination is needed the PCBD is laid out to allow a termination resistor Rt to be soldered in across the RD A and RD B lines The off state bias resistor values can also be changed by removing R8 and R16 and replacing them with through hole components Figure 1 RS 422 485 Connection Diagrams 422 485 4W Device MED
7. per Km at 820 nm the 12 1 dB power budget translates into 2 5 miles This assumes no extra connectors or splices in the link Each extra connection would typically add 0 5 dB of loss reducing the possible distance by 166 m 547 ft The actual loss should be measured before assuming distances Figure 2 Typical Setups Point to Point xX LJ RX Duplex MED100A Mulimade SW1 6 OFF X Lod Ld TX Multi Drop Ring Full Duplex RS 282 RS 422 or RS 485 Device or System Itimods Matin TX MED100A SW1 6 0FF px HA MASTER JAVIS gims H XY 9 LMS 9 LMS voortaan voortaan vooraan NO NO NO RS 232 RS 232 RS 232 RS 422 RS 422 RS 422 or RS 485 or RS 485 or RS 485 Device Device Device or System or System or System Dip Switch Setup The Dip Switch SW1 on the MED100A defines the Table 1 RS 485 Timeout Selection mode of operation when being used for RS 422 or RS Baud Rate Pos 1 Pos 2 Pos 3 Pos 4 Pos 5 R9 Time ms 485 Positions 1 through 5 on the switch determine the 1200 ON OFF OFF OFF OFF 820 KQ 8 20 timeout of the RS 485 driver Because the driver is 2400 ON OFF OFF OFF OFF 430KQ 4 30 controlled by hardware a specific time must be set to 4800 tell the hardware how long to wait for data on the fiber SS EEE T ONTE o side before turning off the RS 422 485 driver If this time 9600 OFF OFF OFF ON OFF NotUsed 1 30 is set
8. ring of MED100As Each transmitter is tied to the following converter s receiver starting at a master node and continuing around to each slave and back to the master By setting SW1 6 to the On position on the slaves all data sent from the master or preceding slaves is echoed back out the fiber transmitter to the rest of the slaves and eventually back to the master node Because all data is echoed back there are special considerations when constructing a multi drop system The master will see its own transmitted data This means that the master device must be full duplex RS 232 RS 422 or four wire RS 485 and that it must be capable of ignoring or otherwise accepting its own echoed transmission Slaves must also be able to accept data from previous slaves in the loop Specifications Features Transmission Line Point to Point Transmission Multi Drop Transmission Dual multimode optical cable Asynchronous half or full duplex Asynchronous half duplex fiber ring Interfaces RS 232 RS 422 or RS 485 Connectors DB25 female for serial connection ST connectors for fiber Dimensions 4 3 x 2 3 x 0 95 in 11 x 5 9 x 2 5 cm Power Supply Connections Terminal blocks Recommended Power Supply PSD100 12VDC Input voltage range 10 30 VDC Temperature Rating 40 to 80 C 40 to 176 F All specifications given using 62 5 125um glass multi mode fiber Table 3 Recommended Maximum MED100 in a Fiber Ring Topology
9. riving on the Fiber Optic receiver is repeated back out the transmitter When set in a Point to Point mode data arriving at the Fiber optic receiver is not sent back out the Fiber Optic transmitter Position 6 must be turned On when the MED100A is to be used in a multi drop ring configuration It must be turned Off when the MED100A is to be used as either end of a point to point communication line See Figure 3 for typical system setups using the MED100A in its different modes Positions 7 and 8 of SW1 determine when the RS 422 485 driver and Table 2 422 485 Switch Settings receiver are enabled Position 7 controls the driver and Position 8 controls the receiver For RS 422 operation set both switches to the an Ae Off position For multi drop RS 485 four wire systems position 7 RS 485 should be On and position 8 should be Off This allows the receiver 2 Wire Mode ON ON to be enabled all of the time and eliminates some possible timing h Ta w problems For RS 485 two wire systems both switches should be in the half duplex On position This disables the RS 422 485 receiver whenever the RS 435 driver is enabled preventing data from being echoed back to the fiber 4 Wire Mode ON OFF side of the MED100A full duplex RS 422 Mode OFF OFF Table 2 illustrates the switch settings for typical setups full duplex Multi drop Operation A multi drop configuration is created by forming a
10. too short the driver could be disabled before 19 2K OFF OFF ON OFF OFF Not Used 0 56 transmission is complete resulting in data corruption If 38 4K OFF ON OFF OFF OFF Not Used 0 27 the time is set too long the RS 485 device may respond 57 6K ON OFF OFF OFF OFF NotUsed 0 22 before the RS 422 485 driver in the MED100A is 76 8K ON OFF ON ON OFF Not Used 0 14 disabled corrupting this response We recommend that the timeout be set for approximately one character time 115 2K_ ON ON ON OFF OFF NotUsed 0 10 or longer The character times for several different baud 153 6K ON OFF OFF OFF OFF 6 2KQ 0 06 rates are selectable on switch positions 1 through 5 If 230 4K ON OFF OFF OFF OFF 43KQ 0 04 you need a different timeout than what is provided R10 460 8K oN OFF oFF OFF OFF 22 KQ 0 02 can be removed and replaced with a different value R9 Table 1 shows different timeout values for the switch positions as well as typical R9 replacement values Black Box Corporation 1000 Park Drive Lawrence PA 15055 1018 Tech Support and Ordering 724 746 5500 Fax 724 746 0746 To contact us about Black Box products or services info blackbox com MED100A 304 pg 3 4 6132 1 Position 6 of SW1 sets the unit in a Multidrop mode or a Point to Point mode When the MED100A is set in a Multidrop mode data ar
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