National Instruments FP-1000 FP1000.fm Page 4 Thursday, July 31, 1997 8:49 AM

Figure 4. RS-232 Connector Pinout

Up to 24 additional FP-1001 network modules can be connected to

this FP-1000 module by using the built in RS-485 repeater. This

repeater makes the RS-485 port of the FP-1000 appear to the

additional FP-1001 modules as if it were an RS-485 port of the host

computer. The pinout of the RS-485 connector is shown in

Figure 5.

Figure 5. RS-485 Connector Pinout

The TX+ of the FP-1000 must be connected to the RX+ of all ofthe

FP-1001 modules, and the TX- of the FP-1000 must be connected

to the RX- of all of the FP-1001 modules. This pair of connections

provides communication from the host computer, through the

FP-1000, to the FP-1001 modules.

The RX+ of the FP-1000 must be connected to the TX+ of all ofthe

FP-1001 modules, and the RX- of the FP-1000 must be connected

to the TX- of all of the FP-1001 modules. This pair of connections

provides communication to the host computer, through the

FP-1000, from the FP-1001 modules.

GND

RTS

DSR NC

54321

9876

NC = Not Connected

GND = Ground

RX = Recieve

TX = Transmit

RTS = Request to Send

DSR = Data Set Ready

Legend:

RX–

RX+

TX–

TX+

GND

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FP1000.fm Page 4 Thursday, July 31, 1997 8:49 AM