Config Error with SQL tags


I have Allen-Bradly ML1400 PLC and when I add its digital I/O to ignition,
I shows symbol of Unknown quality overlay.

Otherwise all analog I/O and memory tags shows good quality.

Please suggest what’s the issue.
Thanx in advance.

Please provide the model number of your 1400 and the address your are trying to access.



Model: 1766-L32BXBA

Address: all On-board DI/DO.

If there is a DO address that is in the SQLTags but does exist in the MicroLogix, the quality for the entire group of DO values will be set to config error. This is because addresses are optimized into a single request and the MicroLogix simply returns an error with no other details or values of the addresses that do exist.

To narrow down on the address(es) that is causing the problem:

  • Remove or disable all your DO SQLTags.
  • From the OPC Browser drag the first DO tag over to the SQLTags.
  • Drag consecutive DO tags one at a time until it fails.

Hi! Thanx for advice.

I tried according to your suggestion and found that Ignition accepts only on-board I/Os and when I insert any expansion module digital or analog, input or output all inputs or outputs shows config error.

I currently have 2 expansion modules:

  1. 16 point DO module
  2. 2point AI and 2 point Ao combo module.