I was upgrading the HMI on an old machine when I ran across this issue. Lines 47 and 48 of the code toggles between two messages on the bottom line display of an Optimate 1500 HMI. The messages change about every 3 seconds.
When I monitor the status of the SP4 bit, it changes state about every 3 seconds. This is a one second bit that is supposed to change state every 500ms. How is it possible to make it change every 3 seconds?
The PLC is a DL205 with a DL240 CPU as a master and another 240 as a slave.