B&B Electronics GW-7552 - Manual - Manual (Page 11)

GW-7552 PROFIBUS/MODBUS GATEWAY User Manual (Version 1.40, Apr/2012) PAGE: 11
Figure 7 The positions of pull high/low resistors in GW-7552 module
2.3.3 RS-485 connection
The RS-485 wiring diagram is shown in figure 8.
The GW-7552 gateway can be a Modbus master or Modbus slave in a local RS-
485 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-485 network
device the four jumpers provided by the module has to be set according to Table
6. The jumpers set the pull high and pull down resistors for the RS-485 port
(Figure 9).
Figure 8 RS-485 connection
GW-7552
RS-485 Port
RS-485