800xA PLC Connect Modbus TCP/IP Configuration
The minimum number of holding registers (HR) is 16. Is it possible to read a block of modbus registers that is smaller than that value? If I create a controller and add 4 tags (reals) for a total of 8 registers the comms fail. I assume this is because my total register count is less than 16. See attached screen shot. Thanks in advance for any help.
Asked 3 years ago
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I think the problem is beause you are using Real data type, try using int data type.
by admin Rank: 24 on 1/6/2015 8:27:08 PM | Like (0) | Report
To follow up on this, the device I am reading from only has a block of 8 registers. There is a gap of 6 registers before the next block. Because of the gap the read fails.
- bhjp
by csanchez411
You can not use real as data tyoe for modbus communication
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