National Instruments Compact FieldPoint cFP-21 Series, User Manual

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Chapter 3 Feature Descriptions
© National Instruments Corporation 3-9 cFP-21xx and cFP-BP-x User Manual
Figure 3-4 shows how to wire several FP-1001 banks in an RS-485 network
controlled by the cFP-2120. Only two FP-1001 banks are shown, but the
cFP-2120 can control up to 24 FP-1001 banks. Install 120
Ω
termination
resistors at each end of the network as shown in Figure 3-4.
Figure 3-4. Wiring for an RS-485 Network Controlled by the cFP-2120
Table 3-3. 10-Position Modular Jack Pin Descriptions
10-Position
Modular Jack Pin RS-232 Signal RS-485 Signal
10 DCD GND
9 RXD CTS+ (HSI+)
8 TXD RTS+ (HSO+)
7 DTR RXD+
6 GND RXD–
5 DSR CTS– (HSI–)
4 RTS RTS– (HSO–)
3 CTS TXD+
2 RI TXD–
1 No Connect No Connect
RXD– RXD+ TXD– TXD+ RX–
RX+ TX– TX+ RX– RX+ TX– TX+
cFP-2120 COM 4 FP-1001 FP-1001
120
Ω
120
Ω
120
Ω
120
Ω