Rslogix 500 - Red Lion G306M HMI

I am having an issue with Rslogix retaining a bit value when the Red Lion goes offline due to a power failure. The setup is for a remote compressoin control and the bit is question is to change the logic from local to remote and vice versa. These are standard "examine if open/closed" bits and not latching.

Thanks in advance.

So, the Red Lion G3 controls the bit, and it changes states when you power cycle the G3? Can you zip and post your files (cd3 and rss)?

Id be interested to see the files as well. How is the G3 configured? What AB product is the G3 talking too?

I don't understand the "issue". Please clarify.

Does the bit stay in its last state when the Red Lion goes offline, or does it change state when the Red Lion goes offline ?

What do you want the bit to do ?

the hmi toggles the bits as it should

the issue is that the micrologix stays stuck in remote(hmi) mode even if the hmi goes offline... this is causing issues to our process due to certian requirements for the need to power off the hmi

normally it would be as simple as the operator making sure he disabled the remote feature before powering it down but "politically incorrect statement goes here"

also i'm forced to use the C2 software due to C3 not supporting the monochrome model

So, you have a control bit which indicates "Remote (HMI) Mode" being active. This bit happens to be turned on when you power down the HMI. Now (assuming here) you have other controls that are disabled because the Micrologix "thinks" the HMI mode is still active and with the HMI powered down you can't turn it off.

If the HMI is connected serially, you may be able to look at the Comms Active bit in the Micrologix to determine when the HMI is no longer communicating. If you will tell us the model of the Micrologix, we can help you identify which bit to examine.

How about using the Red Lion (using a Gateway Block) to transfer a single bit from the Free Running Clock (S:4) from the MicroLogix to a single destination bit in the MicroLogix.

Then add logic in the MicroLogix so if the destination bit hasn't changed for several seconds, then fail back to local/manual control.

i.e. pick a bit that changes every couple of seconds, then use logic that activates if no change has been spotted in 5 seconds in the bit the Red Lion is copying it to.

Using a slow changing bit shouldn't add too much comms traffic.

matt1 said:

How about using the Red Lion (using a Gateway Block) to transfer a single bit from the Free Running Clock (S:4) from the MicroLogix to a single destination bit in the MicroLogix.

Then add logic in the MicroLogix so if the destination bit hasn't changed for several seconds, then fail back to local/manual control.

i.e. pick a bit that changes every couple of seconds, then use logic that activates if no change has been spotted in 5 seconds in the bit the Red Lion is copying it to.

Using a slow changing bit shouldn't add too much comms traffic.

Click to expand...

I use a similar method and it works fine. I move the value of S:4 into an integer. This integer is looked at by my HMI and if it doesn't see it change in a few seconds then it sets and alarm. I also pass this back to my PLC and set an alarm when it doesn't change. I like this method because it works regardless of the comm protocol.