Applies To:
  • CitectSCADA 5.10

I am using the CTAPI point functions to access Citect tags but ctPointRead fails with error code 16406. The device is online, what is going wrong? 

This problem may occur when redundant I/O Devices are configured such that the Standby device appears before the Primary in the devices database. If you experience this problem, it can be resolved by reordering the I/O Device records to place the Primary devices ahead of the Standby devices.

CIT has confirmed this to be a problem in Citect for Windows versions 5.10 to 5.10A. This problem has been fixed in version 5.20.