Installation manual

UNIPOWER
Installation manual PQ Secure
54
7.5.2 Using multiple meters with Westermo GDW-11 GSM/GPRS-modem and RS-485
The Westermo GDW-11 is an example of an industry GSM/GPRS modem with both RS-485 and
RS-232 connections. The RS-485 is an easy solution if you want to connect one or several meters to
one wireless modem/SIM card. Always choose an industry class modem rather than office
equipment when building communications solutions for your meters in substations. The environment
is normally quite different from an office, both regarding physical environment (like temperature)
and EMC environment.
The figure below shows a meter connected to the modem using RS-485 (there are extra connectors
on the RS-485 cable for multiple meter connection).
Figur 39 GDW-11 GSM/GPRS modem with RS-485 connection to a meter
Use the recommended factory setting in the modem for use with RS-485. See below.