Hello,

I would like to connect a Siemens HMI (tp177b pn/dp-6 cstn---- 6ava 642-0ba01-1ax1) with a Delta C200 VFD through Modbus RS485, is it possible?

thank you

Hello mostafa;

Unfortunately, it seems that Siemens has not completely implemented the RS 485 driver for the Modbus RTU communication in the TP 177B (WinCC Flexible).

This quote is from the WinCC Flexible 2008 Communication manual, Modbus RTU, Configuring protocol parameters

:"Only RS 232 has been system tested, there are no guarantees for RS 485 and RS 422.".

https://support.industry.siemens.com/cs/ww/en/view/18797249/9102392843

This is confirmed by other users' experience with the TP 177B:

https://support.industry.siemens.com/tf//ww/en/posts/modbus-communication-with-a-tp-177b/66242?page=0&pageSize=10

If you need more information, possibly on correctives to the Modbus driver, you should contact Siemens directly, through a Support Request (link at the top of this page).

Hope this helps,

Daniel Chartier