Thanks, Hegamurl for the great videos! I enjoy learning about PLCs, but this one I can not figure out.
I have an S7-1200 PLC connected to a KTP 400 Basic HMI, Profinet.
As the picture shows some values in the trend get lost, show like 0 or +- infinity.
After a while, the spikes move to other places on the trend.
Why is it like so? When the trend curve is updated, is all the data for the entire curve sent to the HMI? Is it possible that some values are lost on the way? If so, why are the lost values always replaced by 0 and +- infinity?
Hello,
As the best I can see you monitor temperature. I had similar issue before on another monitoring system. I worked on an injection moulding machine. The trend was ok for 3 - 4 moths after the installation. Last week the company reported they are having some peak on one of the barrel temperature monitoring. Injection moulding machines have a lot of moving units.
- Trend the income value in TIA portal so you can figure out is it a real peak in your signal or just a random issue.
- Do a double check on your probe condition
- Do a double check on your cable
- If the machine do a lot of movement try to figure out which movment is causing interference
- If the cable is not shielded correctly it is a possibility can pickup some random signals which could cause interference on the actual reading
- If your probe is resistance related buy an analogu multimeter " NO DIGITAL " and put it on your probe. Analogue multimeter is more capable to show peaks.
Good luck.