Applies To:
  • CitectSCADA 5.xx, 6.00
  • CitectHMI 5.xx, 6.00

Using CTAPI to read tags that are from a device using the ABCLX driver causes the first tag to display its value correctly but the rest of the tags appear blank. 

This is caused by a blocking issue in CTAPI. The workaround is to change the Protdir.dbf entry for ABCLX from a Max_Length of 2048 to 2032 and Bit_Block from 2048 to 2032 on all Citect computers on the system. This will ensure that all the tags requested through CTAPI that originate from an ABCLX device are able to be read correctly.

It is imperative that this change be made to the protdir.dbf file in the \Citect\Bin and the \Citect\User\Include directories.

Citect has confirmed this to be a problem in CitectHMI/SCADA. We are researching this problem and will post new information here as it becomes available.