MicroLogix Driver Bug

[steves0118]

I found a small bug in version 3.9.9.24 of the EthernetIPforSLCMicroCom that didn't exist in 3.9.9.20.  I mapped the output bits of a MicroLogix 1400 PLC to a BasicIndicator.  It worked fine for the internal outputs (O:0/x), or the expansion module outputs (O:1/x), but not if both existed in the same form.  When they were in the same form the indicators for the expansion module would all simultaneously flash. 

My solution was to put a bit coil in parallel with the output coil on the PLC and map the bits in AdvancedHMI.

[Archie]

This is a known issue in version 3.99x. The problem is reading IO addresses directly. Since IO addresses are not fixed data length as in data tables, the optimizer fails to handle them correctly. In previous versions the optimizer would ignore them and read every address individually even if it was multiple bits in the same word.