Legacy ControlLogix tags are coming in with BAD quality

Ignition
1

Good morning,

I have established communication with a ControlLogix PLC running 20.19 firmware using Ignition’s Legacy AB driver. The Gateways shows the PLC as connected.

ab1
ab11220×70 8.41 KB

I can see the tag values in RSLinx.

ab2
ab2980×179 35.1 KB

I can browse the tags in Designer and drag them into the Tag Browser, but all the values are BAD.

ab3

The diagnostic page for one of the tags shows valid tag definition and tag group.

ab4
ab41680×648 99.9 KB

Any ideas why the values are not coming through?

Thank you,
Ali

2

With 20.19 you need to use the Allen-Bradley Logix Driver (v21+)

1 Like
3

@Tim is correct, and we’re going to be updating the descriptions of the drivers to make this more clear.

Last week we loaded various firmware versions onto a controller here and confirmed that the legacy driver works through v20.18 but in v20.19 they disabled direct memory access (AND they did not implement instance-based access either, so it’s a truly worst-case version to be on performance-wise).

1 Like
4

Thank you very much for the quick solution :smiley: