105U-G Wireless Gateway
User Manual
Page 115
© September 2004
The Fieldbus IN and OUT areas can be configured to a maximum size of 1024 words (2048
bytes) each, depending on the configured fieldbus mappings. The highest mapped location
will correspond to the highest available Modbus register (or coil) available to a Modbus/TCP
client. A Modbus/TCP client must use the appropriate Modbus Coil or Modbus Word
addresses corresponding to configuration software, as well as the correct function code (see
4.10.2 Supported Commands).
Appropriate Modbus prefixes may need to be added to the Modbus Address depending on the
host device. For example, a “word write” fieldbus mapping in the 105G to Modbus location
10, can be read by a host device as 30010 (30000 for an input re 10 as the address).
Alternatively, a “word read” fieldbus mapping in the 105G from Modbus Location 1025, can
be written to by a host device as 41025 (40000 for an output re 1025 as the address).