Hello,

I have a weird problem with CONT_C PID module assignment configured with TIA Portal v17. It does not respond to the setpoint or manual value when my project file is running on the physical PLC and always showed 0.

Then, I assigned a new CONT_C module running with PT3 simulator released by Siemens online in my project file and I used PLC Sim ver 17 to test. Initially, I had the module worked abnormally whereby the output differed by 13 pts lower to the setpoint when the output (and thus input) stabilized. Regardless whatever setpoint value I put, the output differed by 13 pts lower. Then, just around 5 mins, the output decreased gradually to 0 and had never increased since then. 

To perform further test, I created a new simple project file containing only assignment of CONT_C module to a PT3 simulator and tested it with PLC Sim ver 17. Regardless of whatever setpoint or manual value I put, the output does not respond to either value and always shows 0. Some advice on some threads is implemented in my project file, but there is no impact to the CONT_C performance.

I also created a similar program on my other laptop running with TIA Portal v14 and the CONT_C module works just fine and able to run for more than 36 hrs (still running now), no issue at all.

TIA Portal v17 is installed on Windows 10 Pro ver 22H2. The CONT_C technology object is version 1.1, while the system block FB41 (SFB41) is version 1.5.  A screenshot is attached on this thread, while the project file is located on this link for your reference: 

[snip]

I am looking forward to your valuable advice. Thank you.

SS

Hello,

In your screenshot, it seems that the output value high limit LMN_HLM is set to 0.0.

When both values, low and high limit are set to 0.0, then the only possible value that CONT_C can output is 0.0, no matter which setpoint, process value or manual value is assigned.

Regards

Hi Mach11,

yes, you're correct, I missed to set that parameter to a value above 0. The other parameter I missed to configure is LMN_FAC; I need to set that value to be above 0. Upon configuring both parameters to a value above 0, then I can get the output responding as expected. This is just due to my lack of experience of using CONT_C module so far.

So thank you very much for your valuable input.

regards,

SS