adccommunitymod (AutomationDirect) asked a question.
Created Date: April 19,2006
Created By: DArrington
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What in the world? I'm running a DL06, connected via Ecom, and attached to a Maple Systems OIT. As I watch the OK-Online-Run bar on my screen, it frequently gives the red "Error! " warning. I clicked PLC and Link Setup and the Link Info dialog box tells me there are (at the moment) 735520 compledted transfers, 37318 retries, and 11873 errors. Most of the Extended Error blocks state "Timeout error, " but several show "ExError=-20225. " I 've got no idea what this means -- is this a network communication problem, a PLC-OIT communication problem, a gremlin, or some other indicator of my newness to the topic? Thank you for your help. -Dan
Created Date: April 19,2006
Created by: DArrington
New error codes showing: -30465 and -30975. (For what that's worth....)
Created Date: April 19,2006
Created by: marksji
What else is on your network?
What is your timeout setting on the Maple? Try increasing it a bit. I use between 100ms and 200ms on most applications.
What is your poll rate on the Maple? Try increasing it a bit. I try to use as low as possible, but I usually end up with 5-10ms poll rates.
Created Date: April 19,2006
Created by: DArrington
Um, well, everything else is on the network. This is my first shot at communicating with PLC over Ethernet, so my IT guy gave me a discrete IP address and I hung the PLC on the plant network. So about 50 other computers plus printers and such are also hanging out there.
I'm not sure how to find/change the timeout/poll settings on the Maple, but I'll look into that.
I 've just run into something new now: I can't edit a program and send it over to the PLC (it worked last week, but not this week). I get the following notice when trying to download: "Comm error getting PLC mode. " I clicked the Mode button and got these (in order): "Communications error, " "Invalid PLC mode, " and "Keyswitch not in terminal mode. " (The toggle actually IS in terminal mode.)
I'm also having trouble with storing a numeric value on the PLC when given via the OIT. There seems to be some decimal-to-hex converting going on, and I can't tell why. But that's a topic for a different discussion, I suppose.
Thank you for your help. Looking forward to more....
-Dan
Created Date: April 19,2006
Created by: DArrington
Further note: I just disconnected the Ethernet cable and switched back to COM1 serial communication... only one error on the error counter now (more than 4000 completed Xfers), and no problem downloading a change.
Could this have something to do with the list of protocols chosen under Local Area Connection Properties? I'm showing the following items checked:
* Client for Microsoft Networks
* File and Printer Sharing for Microsoft Networks
* NWLink NetBIOS
* NWLink IPX/SPX/NetBIOS Compatible Transport Protocol
* AEGIS Protocol
* Internet Protocol
D.
Created Date: April 19,2006
Created by: Gerry
Do yourself a big favor and disconnect the rest of the network. Use a small hub or switch to connect your devices when experimenting.
"What in the world? I'm running a DL06, connected via Ecom, and attached to a Maple Systems OIT. "
This is because you didn't buy the new C-more panel instead. http://forum1.automationdirect.com/board/biggrin.gif
Created Date: April 19,2006
Created by: marksji
It sounds like you 're overloading your network. 10Mbps and 100Mbps Ethernet has a lot of bandwidth available, but each transmission still takes some time and if you have 50+ other devices trying to talk then you may saturate the network pretty quickly. I'd recommend connecting the PLC and Maple together using a network switch with nothing else connected, I bet things start to work very well again.
Created Date: April 19,2006
Created by: DArrington
Originally posted by marksji:
It sounds like you 're overloading your network. 10Mbps and 100Mbps Ethernet has a lot of bandwidth available, but each transmission still takes some time and if you have 50+ other devices trying to talk then you may saturate the network pretty quickly. I'd recommend connecting the PLC and Maple together using a network switch with nothing else connected, I bet things start to work very well again.
Rats. At the moment, the intent is to use the Ecom to join the PC and the PLC for programming. That allows me to connect the OIT to Port1 of the PLC (I haven't figured out how to make Port2 talk to the OIT).
If I can get network comm successful, then I can save myself (and our maintenance guys) a bunch time by not having to walk from one side of the building to the other for program checks. If I have to put PLCs on a separate network, then how big a thing is it to get to the PLC network from my PC (on the main network)?
I'll check with our IT guru about bandwidth usage -- perhaps he can see if that's what's stepping on my Ecom use.
Thanks again! Any ideas what those numbered error codes trying to tell me?
Created Date: April 19,2006
Created by: marksji
Depending on how good your IT guy is and how good the equipment he has to work with is he may be able to give your PLC, Maple, and PC priority on the network; this may help some(actually it should help a lot).
Find the poll and timeout values and get those changed. Those two parameters will probably do more for you than anything else.
No clue what the error codes mean exactly. They are probably application specific, so some engineer at Maple may be the only person those make any sense to.
Created Date: April 20,2006
Created by: Tech Guy
In your case the numbered error codes are just the ECOM's way of saying, "Hey, I can't talk. There is too much traffic. " They are numbered different because each code is for a different type of error, whether it be a collision, or no reply from one end or the other, or just a lost packet. It all means the same thing. The network is too busy.
The bottom line is, the PLC's and HMI's need to be segregated from the office network. Your IT guy might use a managed switch, a gateway, or even possibly a router to accomplish this. But they do need to be seperated. I am surprised that no one in the office has complained about how slow the network has become. PLC's and HMI's eat up a lot of bandwidth since they are constantly passing data back and forth. Look into getting these devices totally seperated from the rest of the network. Your IT guy should be able to do this and still leave you access from the office network for programming.
Created Date: May 19,2006
Created by: glenncovington
If it is just a few pc's you could just add a second ethernet card in each one and tie them on to the PLC network. This way they would be on the LAN with the main card and on the PLC network with the second card.
Warning: For DirectSoft you may have to disable the primary card when trying to get online or you may end up getting a "Transport Protocol Error ". It doesn't seem to know which NIC to look for the PLC's on.