KepServerEX and Modicon M211 Modbus TCP Problem

3 posts in this topic

hi All,

I am using KepServer EX V4.0 to read and write network objects ( %IWMx & %QWMx) of M221 PLC via Mobus TCP but it does not succeed although quality show good on OPC client meaning value of registers was changed in OPC client but it did not change in PLC program and vice versa. The unit ID of M221 is 247 and same for device ID in KepSever. Please see attached screenshots of configuration and advise.

Thanks so much in advance

Kind regards,


Kepserver-Device Properties.PNG

M221-Modbus mapping.PNG

M221-Ethernet IP.PNG


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simulate device is checked

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You have the device in the server configuration set to simulated mode. This forces the Server to do a loop back on the device and you are now only reading from cache and not going out to the device at all. If you were to write to a tag you would see the value returned in the client but it would not be written to the physical device just to the cache that is allocated for that tag.

Un-check that setting and you should start talking to the device. it the device is not responding you will get an error in the server for that.

You may also want to consider updating to a newer server version. V4. is no longer sold or supported by Kepware/PTC.

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