Hello.

Recently got project need to link up KTP700 basic DP and Beckhoff IPC via Modbus RTU (RS232).

HMI have been equipped with RS485 to RS232 converter, but end-up HMI showed error 190011 (Variable could not be written to PLC) and connection is interrupted.

The HMI is programmed via TIA Portal V17.

HMI is tried to connect and link to PC via ModSan and Mod Poll, but timeout error shown. Go online on TIA Portal also unable.

Need some guide on how to go online on HMI to PC, as well as how to ensure the Modbus RTU connection is OK.

Guidance on setting HMI device also needed.

Please let me know if any other information are needed

Murof

Hello cyk1019

It will not help you to go "online" in TIA Portal to the HMI. It has no online diagnostiv interface and you will not see any state of your communication.

If you show system alarms then there is also an alarm that indicates if the connection is established or not at the beginning of RT Start.

Modbus RTU is only developed for Modicon Modbus PLCs. I do not have experience with Beckhoff so I cannot give any tips here:

Have  a look at the manual perhaps it helps:

https://support.industry.siemens.com/cs/ww/en/view/109813307/77442661899

Bye Murof

 Hello, Mr Murof.

Error code 220007 (Connection is interrupted) is appeared once HMI is started-up.

Thus, now in the midst of troubleshooting, would like to know where the connectivity comes from, either IPC or HMI.

Let say, if all the setting of HMI are done accordingly to what the manual stated, any method that can be suggest to check the Modbus connectivity of HMI? Because with the use of ModScan and ModPoll, keep on blinking error 220006 (Connection is established) and error 220007 (Connection is interrupted).

I would like to ensure HMI programming is correct and able to read and write to the designated Modbus address before proceed to the next.

Thanks and regards,

cyk1019