Connection To A Controller; Modbus Mapping; Master Status - Softing Modbus mbGate PA User Manual

Connection to a controller

5
The following chapter describes how to establish a Modbus connection using the engineering systems
Schneider Unity Pro and Siemens TIA Portal.
5.1

Modbus Mapping

The Modbus Gateway maps the statuses of the PROFIBUS masters and the PROFIBUS slaves to a number
of Modbus registers. In addition, the gateway offers a register-based command interface for acyclic
reading and writing of PROFIBUS device parameters.
Select MODBUS TCP
5.1.1

Master status

The operation mode of the PROFIBUS master can be read and changed in the low bytes of Modbus
registers 8500, 8628, 8756 and 8884.The following diagram shows the Modbus registers used for the
segments of different Modbus Gateway .
Register
8500
8628
8756
8884
When a PROFIBUS master is started it takes on the operation mode Stop. In this mode, PROFIBUS input
data is read but no output data is written to the PROFIBUS slaves. If you want the PROFIBUS master to
write output data to the PROFIBUS slaves, you must set the master to operation mode Run by writing
value 3 to the corresponding Modbus holding register.
Version EN-092019-1.21
Mapping.
mbGate PA – 4 CH
Status PA-0
Status PA-1
Status PA-2
Status PA-3
mbGate PA - 2 CH
Status PA-0
Status PA-1
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Chapter 5 - Connection to a controller
mbGate PB
Status PA-0
Status PA-1
Status DP-0
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mbGate DP
Status DP-0
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-
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