Applies To:
  • CitectSCADA 6.XX
  • CitectHMI 6.XX

I am using the S7NT400 protocol and getting error 0x101b in the probe window. Although I do not see #COM displayed on any page, I am concerned that there is a problem with my communications.
What does the error code 0x101b mean?

The error in the probe window is not actually a driver error. It is actually from the COM layer where probe operates.

The error 0x101b is actually GENERIC_STANDBY_ACTIVE.

So in this case it means that this request was serviced by a standby I/O device, not the primary device.

This can occur for a number of reasons. Most likely is that the Primary I/O device was offline, or it received a timeout for the request.

probe, 101b