Owner`s manual

87
The V71 RJ-45 port uses the following signals for current
loop line interface with active transmit and active
receive:
DB-25 PIN/SIGNAL DEFINITION FOR CURRENT LOOP (ACTIVE TX ACTIVE RX)
Pin# Current Loop Signal Direction Description
7 GND ---- Ground
9 TX+ Output Transmit Data (+)
11 TX- Output Transmit Data (-)
18 RX- Input Receive Data (-)
19 RX+ Input Receive Data (+)
25 GND ---- Ground
Figure 22 below shows the basic active transmit circuit,
Figure 23 shows the basic passive receive circuit, and
Figure 24 on the following page shows the basic active
receive circuit.