Display text/
Symbol
Description
Swapping is not activated. The sequence of
reading and writing of bits is the same. Push the
symbol to activate swapping.
Swapping is activated. The sequence of reading
and writing of bits is inverse.
Push the symbol to deactivate swapping.
Push these symbols to select or deselect this type
of bus communication. After using these symbols,
restart the PLC by switching the main switch off
and on.
Push this symbol to revert to the previous menu.
Technical data of the interface
Cable type: Shielded twisted-pair cable
Max. cable length: 1000 m
Data bit: 8
Stop bit: 1
Number of holding registers for reading (F03): 0 … 9 (40001-40010)
Number of holding registers for writing (F16): 16 … 19
(40017-40020)
The master must be programmed accordingly.
Modbus functions
Registers for reading and writing are separate registers, even if they
have the same number.
Depending on the master, it can be possible that the bits in register
are inverse (bit 0 of first byte in data block is bit 0 or bit 8 in register
“xxx”). Also words of real values can be inverse. In both cases use
the swapping function.
Related information
8.8.9 Output addresses (Polydos to SCADA)
8.8.10 Input addresses (SCADA to Polydos)
8.8.6 PROFINET (S7-communication as server)
The "Permit access by PUT/GET communication from remote
partner" function is activated by default in the properties of the CPU.
The communication area in the PLC memory is DB100.
Writing into different communication areas can destroy the
PLC program.
8.8.7 Interface data
In this menu, the bus communication interface data can be viewed.
It shows the status of signal exchange between the SCADA system
and the Polydos PLC.
Menu action
Required user level
Access menu
Change settings
3
System Service
PD412E-D2340
Fig. Interface data
Symbol
Description
Push this symbol to revert to the previous menu.
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English (GB)
