Ametek Western Research IPS-4, Руководство пользователя

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Modbus Communication Interface
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8-3
Analyzer Modbus Interface Parameters
A number of analyzer Modbus interface parameters need to be set up in
order to establish communication with the Modbus master. These pa-
rameters are accessed via the service port on the analyzer using a service
program running on a PC.
Modbus Address
The analyzer needs to be assigned a Modbus slave address, which can be
a number from 1 to 247.
Modbus Functions
As the Modbus protocol is designed for communication among Program-
mable Logic Controllers (PLCs), not all Modbus function codes supported
by a slave PLC are applicable to the IPS-4 analyzer. Only the following
relevant function codes are implemented:
Code Description
03 read multiple holding registers (4x references)
06 write one holding register (4x references)
16 write multiple holding registers (4x references)
In accordance with MODBUS protocol specifications, all address referenc-
es in Modbus messages are numbered relative to zero. For example, the
first holding register in a Modbus slave being referenced as 40001 would
be addressed as 0.