ICP DAS USA GW-7552-B User Manual page 10

2.3.2 RS-422 connection
The RS-422 wiring connection is shown in figure 5.
The GW-7552-B / GW-7552-M gateway can be a Modbus master or Modbus
slave in a local RS-422 network. Depending on whether the gateway acts as a
Modbus master or as a Modbus slave and on the number of devices connected to
the RS-422 network device the four jumpers provided by the module has to be
set according to table 5. The jumpers set the pull high and pull down resistors
for the RS-422 port (Figure 6, Figure 7).
GW-7552-B/GW-7552-M
Figure 5 RS-422 connection
Table 5 Jumper position for the RS-422 port
Pull high/low resistor
GW-7552-B / GW-7552-M PROFIBUS/MODBUS GATEWAY User Manual (Version 1.60, May/2017) PAGE: 10
RS-422 port
Enabled
(default)
Disabled
Condition
 The GW-7552-B / GW-7552-M is the
master in RS-422 bus or
 the number of devices connected to
the RS-422 bus is less than 10
 The GW-7552-B / GW-7552-M is a
slave in RS-422 bus or
 the number of devices connected to
the RS-422 bus exceeds 10
RS-422 port