Hi,

please post your program and explain what Bit you use fgrom the HMI in your LOGO! program. Then I can try to help.

Hi,

start the online test in LOGO! Soft comfort V8.1 and check the signal from the HMI on the relateed NI.

If it goes to "0" after a wile (without pressing the buton again on the HMI), then your button operates as a momentary buttom.

In this case I would recommend to connect the related NI to a Puls Relay in LOGO!. Then any time you press the button the signal in LOGO! change.

If the signal from the HMI does not change, then any other influences the NI.

Example:
You use NI which is V0.0 in LOGO!. At the same time you also use the VM mapping table to get parameters in LOGO!s Vmemory for any other use. In the VM mapping table the parameter is mapped to VW0. In this case you have a memory overlap.

Means:
Your button use V0.0 and the VM-mapping VW0. VW0 is a 16 bit value starting from V0.0 ..V0.7 AND V1.0 ... V1.7. So two sources influence the same bit V0.0.

Hope this helps