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Q3: How are the local registers mapped to the polled data in a MDC-700?
A3: Only the function code 01/02/03/04 can be used in the polling definition section
01: Read Coil Status (Read DO)
02: Read Input Status (Read DI)
03: Read Holding Registers (Read AO)
04: Read Input Registers (Read AI)
Refer to the example below,
The MDC-700 will sort the order of polling data by COM port number and the sequence of polling
definition; and then map the local registers corresponding to the data type (DI/DO/AI/AO) by the
order of polling data. So the data comes from different slave devices with the same type will be
saved in continuous registers, and a Modbus mater device and read the data on a variety of slave
devices with one Modbus command.
# UseComPort SlaveModbusID FunctionCode RegStart
Addr
RegCount Timeout
EventProcess
Preset
Value
*
1
1
1
0
8
2
0
*
1
1
2
0
8
2
0
*
2
1
1
0
4
2
0
*
2
2
2
0
4
2
0
*
2
3
3
0
4
2
0
*
2
4
4
0
4
2
0
Read DO
000000:000007
000008:000011
Read DI
100000:100007
100008:100011
Read AO
400000:400003
Read AI
300000:300003
COM1
Read DO: 000000:000007
Read DI: 100000:100007
COM2
Read DO: 000000:000003
Read DI: 100000:100003
Read AO: 400000:400003
Read AI: 300000:300003
