AXC F 2152 with Analog Input - Wrong (analog) values

PLCnext Technology & PLCnext Controls
1

Hi, I have 2 laser distance sensors (SICK DT35) with analog output (0-10V). They are connected to the analog input channels 1 and 2 and the gnds are connected to common ground (each).
In a program I’ve setup 2 external variables UINT which are connected to process data item ai-1/ IN01 and 1i-2/ IN02.
In debugging mode, I can see that the values somewhat changes with moving the sensor around, but something weird happens: If I move one sensor and the other sensor is still, somehow it changes the values of the not-moving one. I’ve checked the linkage more than once and I don’t think that there is an electrical/ cable problem which does some weird disturbances.
However, I don’t know what it could be either. Maybe an overflowing buffer? Is the size of 16 bits correct for the ADC with 12 bits? Also, I cannot get to 10_000 mV, the max value is around 5xxx which is also weird since it is the 0-10V smart element.
Some ideas there? Thanks!

Changed order.jpg

2

Hello robin4clx,

which AXL SE module are you using?
How are the sensor cables shielded?
Have you ever tried whether the behavior changes if you assign channels 1 and 3, for example?
We are not aware of any interference between the channels.
You can also contact support@phoenixcontact.de directly, where there is already ticket #448053 for your query.

3

Hi, I am using the 0-10V Analog Input module: SE AI4 U is the name I think.
Seems like it solved! The problem seemed to be related to the GNDs not being connected (of the sensors and the PLC).