CMMO-ST-C5-1-LKP , FESTO, Error 0x47 Modbus connection with master control

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The problem refers to Festo servodriver.

I have a Festo CMMO-ST-C5-1-LKP servodriver, I want to connect this to NX PLC via Modbus TCP.

If I send a Modbus frame from the Festo controller in which I want to allow movement and unlock the brake, immediately after executing these commands, the controller issues error No. 47 "Modbus connection with master control"

When I send a frame in which I want to reset this error (according to the documentation CCON.RESET = 0-> 1, CCON.ENABLE = 1), this happens the same: the error is reset but after a while again the same error appears.

In the documentation this error is described:
"The Modbus connection to the controller has been interrupted.
Check the connection and perform a reset.
- Resettable: Error can be reset immediately.
Definable error reaction (s): B, C, D, E, F, G
- For parameterisation as a warning: "The warning disappears."

This description shows that communication is lost. But how is this possible since I can send another Modbus frame and it is received by the driver?

In the attachment, documentation describing the bits of the Modbus TCP frame for this driver and a description of the errors.

Bits which I send and I recive I see in the Festo Configuration Tool - the connection and control over this program does not cause any errors.

Maybe I should also configure something in the Festo driver so that this error does not appear?

Thanks in advance for your help.


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Cannot really say anything since we don't know how you made the program... also it'll up to you to set the CMMO driver parameters in order for the Modbus to work properly.

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