Hello all,
I'm working on a project using an AB CompactLogix PLC and 2 Red Lion HMIs (G3) running Crimson 3.0.
The PLC and the HMIs are connected to an Ethernet switch, this way establishing all the communications through Ethernet.
The HMIs run identical version of the same project, both reading from and writing to the (same) PLC.
I implemented Hand-OFF-Auto selector switches on the screen to run the motors. Each pair of selector switches (one on each HMI) corresponding to a particular motor is tied to the same tag on the PLC, so if one selector is changed on one of the HMIs, the identical selector will change on the other HMI(with a delay of 1 or 2 seconds, though).
Now it comes the problem. Let's start from the situation where the selector switch for a particular motor is at the "Hand" position (the selector switch on both identical screens on each HMI are at the "Hand" position ), so this motor is running. Then I change the selector switch on one of the HMIs to "OFF". What happens (randomly) is that the motor stops (as expected), but after a few seconds(1 or 2), it starts again, and then finally stops. I think that the reason for this unexpected re-start before the final stop is because the selector switch on the other HMI is still at the "Hand" position for a couple of seconds before changing to "OFF"(remember the delay).
Is there a good workaround for this issue?
Thank you!
I'm working on a project using an AB CompactLogix PLC and 2 Red Lion HMIs (G3) running Crimson 3.0.
The PLC and the HMIs are connected to an Ethernet switch, this way establishing all the communications through Ethernet.
The HMIs run identical version of the same project, both reading from and writing to the (same) PLC.
I implemented Hand-OFF-Auto selector switches on the screen to run the motors. Each pair of selector switches (one on each HMI) corresponding to a particular motor is tied to the same tag on the PLC, so if one selector is changed on one of the HMIs, the identical selector will change on the other HMI(with a delay of 1 or 2 seconds, though).
Now it comes the problem. Let's start from the situation where the selector switch for a particular motor is at the "Hand" position (the selector switch on both identical screens on each HMI are at the "Hand" position ), so this motor is running. Then I change the selector switch on one of the HMIs to "OFF". What happens (randomly) is that the motor stops (as expected), but after a few seconds(1 or 2), it starts again, and then finally stops. I think that the reason for this unexpected re-start before the final stop is because the selector switch on the other HMI is still at the "Hand" position for a couple of seconds before changing to "OFF"(remember the delay).
Is there a good workaround for this issue?
Thank you!