Digital value error.

[buddhaman001]

So i have a scada system, of course, and it is doing a most odd thing.

So we are monitoring fine blah blah blah then for some reason be it bandwidth or connection issues (unsure at this point) quite a few of our digital tags go to an error state, understandable if there is indeed an error....but they stay that way until the software is restarted.

Shouldn't factorytalk attempt to refresh the data anyway? or is there a setting that ive missed.

also this is not replicatable, and happens at seemingly random intervals, could happen once a week could happen once a month or not at all. also our analog values seem to be unaffected even if EVERY digital bit being monitored for a certain site goes into error, but usually it is only one or two bits that go to error at a given time, usually our softstart motors sometimes our power monitor.

what gives plctalk?

 

[rdrast]

What communications server?
What HMI software? (SE Distributed, SE Station, ME?)
What PLC's?
What kind of network?

 

[buddhaman001]

Not sure what you mean by communications server. something im probably using but dont know the proper name for yet.

software, is ME on a 6 core with 8 gigs ram and mirrored array
plcs are all 1100 micrologix (some with analog expansion modules)
and the network is a dedicated cell network on a seperate subnet.

 

[buddhaman001]

Oh also they were talking about a data collector, i figured out how to make one out of another micrologix (only 15 plants) to retrieve the data in sequence instead of a big burst, and then jsut have the hmi update off of that, but im at the same time worried that it will just pull an error value off of the field plcs and we may still get error values....man sometimes it sucks being new to a field, specially as a sole programmer haha.

 

[buddhaman001]

Ok, communications server, dont have one of those. Honestly never even had the chance to play with one but looks like fun.

no our network is faaaaaar simpler than that level, pretty much goes

scada server > unmanaged switch > cell connection

the only reason the switch is there is we are going to have a clone scada server so in case anything happens to the origional all they have to do is flip a switch and start the backup while the main is under repair. (usb key liscence registration etc)

all devices are setup on static routing and ip adresses even across the cell part of the network, alongside security settings i wanted to make it very difficult for anyone to get in from the outside world

 

[rdrast]

Cell connection?
For what it is worth, Rockwell's FTView software is about the most unreliable piece of software in the world. It doesn't usually try to reconnect to devices or tags that it has error out. Do the tags come back on a restart of the hmi software?

Anyway, if you want any help, you need to give answers to what I listed above at LEAST. What software, What Versions, what OS, What communications server (With ME, I'm guessing you are using RSLinx Enterprise), What are you trying to talk to.

I'm not a mind reader.

 

[buddhaman001]

Ohhhhh rslinx enterprise is the com server...gotchya

Cellular connection. Spread across rather large distances (bout 500sq miles) this is the solution the guy went with.

They actually do come back after restarting the hmi and right away at that.

Development software: Factory Talk View Studio v7.00.00 (CPR 9 SR 6) Pack 0 Build 13
Server software should be the same thing but i can't get to it atm to pull that info.
OS:Windows Server 2008R2
Com Server (now that I know it's proper name): RSLinx Enterprise
Talking to: multiple Micrologix 1100 (all have 4 channel analog extenders to be compatible with our 4-20 transducers)
Net connection ratings (according to provider): 5mbps (so probably 1mbps up if they hold to standard packaging)

We average about a 30ms response time across the board thusfar.

Software is configured to refresh once every 2 seconds.

 

[buddhaman001]

Well I brought the refresh rate of my hmi server down to 10 seconds. Seemed like it was going to work for a while but just recieved a call from the customer notifying me of a couple of error'd pumps. Any further thoughts on what it could be, or any way to force a refresh of an error'd tag?

 

[buddhaman001]

Still experiencing this issue, is there a way to make digital tags dumb so that they just keep updating even if they stray into an error value? (or loss of communication?)

 

[rdrast]

There is somewhere a pre-configured display screen for Linx Enterprise communication status, I'd suggest putting in one of them for each PLC you are trying to talk to first, and then look at what exactly is failing when you lose the tags.

Linx Enterprise really does not gracefully recover from missing packets.

 

[buddhaman001]

Oh really? Ill be checking into that though so far it only seems to be our digitals, also how long does this hold the log? or can it hold it indefinitely? Mainly because the units are about 2 hours from me, and 30 minutes from central in all directions, so I'll need plenty of time to be able to get to them! Also thanks for giving another troubleshooting route!

EDIT: I misspelled a few things.