Hello,
i set up a Client and use the server "Modbus-Slave" for test.
I want to read out 2 holding registers with the adresses 40097 and 40098. This addresses are defined in the slave.
But the output TCP frame shows just 96 with two elements insted of 40096 with two elements.
It generates exeptioncode 2.
If i define the slave with the addresses 97,98 , it works.
What can i do, to read out the addresses 40097 and 40098 ?
See in pictures below.
thanks for your help.
PV780T, PVCS 2.8
ModbusTCP data address fail
- Roger Miauton
- Posts: 4
- Joined: Mon May 26, 2014 12:26 pm
ModbusTCP data address fail
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- Modbus slave.PNG (60.38 KiB) Viewed 66 times
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- PV Modbus1.PNG (84.8 KiB) Viewed 66 times
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- ModbusTCP frame.PNG (76.3 KiB) Viewed 66 times
- boyce
- Enovation Controls Development
- Posts: 322
- Joined: Wed Sep 08, 2010 5:09 pm
Re: ModbusTCP data address fail
Looks like it is as expected. The leading 4 indicates it's a holding register. The data address is 2 bytes, does not include the leading 4.
- modbustcp.JPG (74.29 KiB) Viewed 44 times
Boyce Schrack
Enovation Controls
Enovation Controls
- Roger Miauton
- Posts: 4
- Joined: Mon May 26, 2014 12:26 pm
Re: ModbusTCP data address fail
ok,
when this is the original modbus definition, then it seems that the Modbus protocol in the slave device in not correct implemented.
Unfortunately, i get an "illegal data address" response when i use the Murphy as client.
I will ask the producer of this device (photovoltaik inverter), and i hope they can adjust the address range of the slave.
Thanks for this information.
Johannes
when this is the original modbus definition, then it seems that the Modbus protocol in the slave device in not correct implemented.
Unfortunately, i get an "illegal data address" response when i use the Murphy as client.
I will ask the producer of this device (photovoltaik inverter), and i hope they can adjust the address range of the slave.
Thanks for this information.
Johannes