292 Modbus – CODESYS 2
WAGO I/O SYSTEM 750 XTR
750-8202/040-001 PFC200 2ETH RS TELE XTR
Manual
Version 1.2.0, valid from FW Version 03.01.07(13)
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9.4
Data Exchange
Modbus data exchange is performed in cycles or acyclically using Modbus
services. The type and number of usable Modbus services depends on the area
that is addressed. There are generally four Modbus-relevant address areas in the
PFC200:
•
Modbus input process image
(Modbus Input) – is an area in the PIO (PIO
= Output Process Image), in which data from the PLC is provided in cycles
exclusively for Modbus Read services.
•
Modbus output process image
(Modbus Output) – is an area in the PII
(PII = Input Process Image), in which Modbus Write services provide data
for cyclic reading by the PLC. Modbus Read services are also acceptable in
this area.
•
Modbus flag area
– is an area, in which both Modbus Read and Write
services can be executed.
•
Modbus register
– is an area, in which the WAGO specific information and
configuration registers are contained. Only Modbus register services may
be executed in this area.
