Self rebooting (resetting) Micrologix 1100

[RFburn]

Hi all.
We have some Micrologix 1100 PLC's monitoring some remote equipment over an RF link using the Ethernet Port. At the Hub is a WebPort WP4520 polling each site and updating a website and emailing any alarms.

This works fine except sometimes we lose the Ethernet connection for some reason, which isn't a big deal as the remote PLC's are monitoring non-critical (but nice to know) parameters. Mostly the PLC's recover and communications resume's, but sometimes the only way to get them communicating is to drive to the site and cycle the power on the PLC.

I can't find a command within the PLC to reboot it. Does anyone know of an elegant way to self reset a Micrologix 1100 without having some external timers and relays to cycle the power on it.

Its not a programming fault as we have exchanged reliable sites with ones having the comm failure problem and its a site issue. The digital RF links used are T1 and the Ethernet port is not its main function and so is not
supported for what we are using it for. Therefore at the furthest sites where Forward Correction Errors pop up, it seems to drop the Ethernet and concentrate on keeping the T1 running. This is fine as the Ethernet is up 99% of the time. Just sometimes driving a 3 hour round trip to cycle the power is a pain.

Any ideas?

thanks!

 

[danw2]

You might consider the Webrelay:

http://www.controlbyweb.com

Although I use it on all remote Windows boxes in order to be able to power cycle/restart a Windows box remotely, I suspect that the use of its ping facility might be able to detect a failed ethernet link. no ping response, no ethernet. The Webrelay is basically an IP addressable relay which one can configure and control via a web page.)

I've never used it, but it's my understanding that a feature called auto-reboot can be configured so that the web relay generates a ping, listens for a response from the PLC and in the absence of a return message or messages, would cycle the its relay/power.

The documentation isn't 'polished', but the device works. Be aware that the drop down choices change depending on selection.

As I recall, when the auto-reboot option is selected, under relay input options, then selections like
- ping a device on periodic basis
- specify IP address,
- specify interval for ping,
- specify # of failed pings that constitutes a fault, - - what a 'reboot' means appear.
appear.

Dan

 

[jde777]

I know there were ethernet communication issues with certain revisions of the ml1100. You should upgrade to the latest firmware.

http://www.ab.com/programmablecontrol/plc/micrologix1100/downloads.html

 

[RFburn]

Jde,
Thanks for that notification of the ethernet comm issues. I'll look into the latest firmware.