Hi everyone!
I have some devices (PLCs connected to scada through a gateway) that often go in “browse pending” or “Download Mode”, so tags from that devices aren’t updated and It happens to lose data.
Every time I saw devices in this status, I tried to disable and then to enable device and it works.
Which could be the reasons of this beaviour and, is it possible to set an alert that send me an e mail in case of Browse pending (so the status is still connected)or download mode?
I’ve had to do this when we had a quite unreliable network, and in 1% of the cases, the PLC wouldn’t come back online after losing connection. It would get stuck in “Connecting” status. But I’ve never seen a PLC hang in the statuses you mention.
Thank you for your help…
our PLCs are Allen Bradley and yes I’m talking about device connetivity.
I saw that this system.device function allows me to see (for example) my device list but I don’t know
if I can see device status to put an alert.
thank you!
That being said, I usually only keep browsing on long enough to do the initial development. After that, I will turn it off and use system.device.refreshBrowse() to update only when necessary.
Even with “Disable Automatic Browse” checked the CompactLogix devices status will switch back and forth between Browse Pending and Download without going back to Connected.
If I just edit the device and save (no changes) it will go back to connected and stay that way for several hours. Then the problem comes back.
What is the solution?
It is happening constantly, randomly seemingly moving through each EIP protocol connected machine.
Sometimes 2 at a time, sometimes just 1 at a time.
I will do a support ticket probably.
Thought maybe someone found a solution before.
In my case, only up to 2 plcs disconnect at a time.
Note more than 2.
So I thought maybe something is begin overrun.
For my system, it looks like pushing 14 things through a hole, and a random 2 fallout regularly.
How do I know if this is a physical connection issue?
Or how do I know if this is an overrun situation?
I have timestamps for the resets.
They seem kind of far apart though, so not a physical connection issue?
Maybe many happened at 10:42, so it is physical?
Below is a a list of recent resets on the log, and maybe the timing can help with troubleshooting.
I numbered the machines, but one is a group of machines on the other side of the facility.
The "group" one is like one plc for many machines.
Do they all run into a common switch? Is the switch powered through an APC? I've seen the battery start to fail in those, and when that happens, they will randomly cycle.
It's not your fault. With confidence, tell the network guys that the problem is on there end, and I'm sure they will find the problem and fix it.
If it is legitimately too many devices trying to talk over each other (usually 500+), then they will simply need to split the network with a router or a switch with routing capabilities. However, if the network has been running for sometime without this problem, and no devices have been added recently, then it's probably a simple hardware or cabling issue.