Welcome to our new forum
All users of the legacy CODESYS Forums, please create a new account at account.codesys.com. But make sure to use the same E-Mail address as in the old Forum. Then your posts will be matched.
Close
In CodeSys 2.x it was possible to just to declare a variable like this. PLCTag AT %MW0 :INT; ( Variable Int modbus addr 12288)
Then it was possible to access this variable from a Scada/HMI via Modbus.
If a counter in the controller is counting on PLCTag register, it was possible to read that value in the Scada/HMI but also possible to change from the SCADA/HMI side.
Now in CodeSys 3.x it seems that this is not possible anymore. CAN THAT really be true???
Thx
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hello,
I am working on a Project that consists on controlling IAI axis via MODBUS RTU with a Raspberry pi based on codesys, and I need some support. I would like to know if there is any function to write variable´s values directly in modbus communication channels. Instead of linking them in the Reading and writing channels, I want to know if there is any function to write these variable´s values in the communication channels automatically.
I will be waiting for your answer.
Thank you.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Sorry I'm a bit confused, entirely on my end. Do you mean writing a variable to a channel without using the modbus function codes?
As in instead of writing register 100 with function code 6 you want to send 6x0100 or something like that? I'm not sure if I'm correct about it being 6x0100 so I apologize if I'm incorrect.
I honestly don't know. Try looking at the IoDrvModbus library.
Hi Everyone
In CodeSys 2.x it was possible to just to declare a variable like this. PLCTag AT %MW0 :INT; ( Variable Int modbus addr 12288)
Then it was possible to access this variable from a Scada/HMI via Modbus.
If a counter in the controller is counting on PLCTag register, it was possible to read that value in the Scada/HMI but also possible to change from the SCADA/HMI side.
Now in CodeSys 3.x it seems that this is not possible anymore. CAN THAT really be true???
Thx
If your scada dont cyclically writes, it's still possible. (This implies your plc supports modbus RTU slave or modbus TCP server)
Hello,
I am working on a Project that consists on controlling IAI axis via MODBUS RTU with a Raspberry pi based on codesys, and I need some support. I would like to know if there is any function to write variable´s values directly in modbus communication channels. Instead of linking them in the Reading and writing channels, I want to know if there is any function to write these variable´s values in the communication channels automatically.
I will be waiting for your answer.
Thank you.
@johant
Sorry I'm a bit confused, entirely on my end. Do you mean writing a variable to a channel without using the modbus function codes?
As in instead of writing register 100 with function code 6 you want to send 6x0100 or something like that? I'm not sure if I'm correct about it being 6x0100 so I apologize if I'm incorrect.
I honestly don't know. Try looking at the IoDrvModbus library.
https://help.codesys.com/webapp/_mod_f_libraries;product=core_modbus_configuration_editor;version=3.5.15.0
Last edit: Morberis 2020-07-08