slc 5/05 very slow upload and online edit

phinix

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• Jun 30, 2010

• #1

hi you all

i am dealing with this problem for 2 weeks with no results
i have 4 slc's 5/05 and 1 micro 1100 with cimplicity all r ethernet connected , 2 of the slc's r very slow to respond
with on-line editing , and full image upload (up to 40 minutes)

- memory on both is not to low
- all slc's configiration is the same including 10/100 auto
negotiate
- only about 5 msg between plc's running every 3 sec
- no port errors on switch diagnostics
- average scan time 500 ms

hope you have an idea
thanks

 

curlyandshemp

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• Jun 30, 2010

• #2

phinix said:

hi you all

i am dealing with this problem for 2 weeks with no results
i have 4 slc's 5/05 and 1 micro 1100 with cimplicity all r ethernet connected , 2 of the slc's r very slow to respond
with on-line editing , and full image upload (up to 40 minutes)

- memory on both is not to low
- all slc's configiration is the same including 10/100 auto
negotiate
- only about 5 msg between plc's running every 3 sec
- no port errors on switch diagnostics
- average scan time 500 ms

hope you have an idea
thanks

Click to expand...

First thing I would do is verify the integrity of the ethernet cables with a media tester.

 

JesperMP

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• Jun 30, 2010

• #3

phinix said:

- average scan time 500 ms

Click to expand...

That is a crazy scan time.
It will as a sideeffect result in slow comms.
Since the memory is "not so low" I suspect a genuine programming error, i.e. recursive code gone bad.

edit: I am assuming that you by "scan time" mean the scan time of the CPU.
If you mean the polling time of the HMI software, then 500 ms is not so unusual.
In that case, checking the CPU scan time is still important.

 

Last edited: Jun 30, 2010

phinix

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• Jun 30, 2010

• #4

sorry , scan time is 50 ms not 500 ms ( 5 [X10]ms )

 

OkiePC

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• Jun 30, 2010

• #5

We have a heavily loaded 5/05 with about a 65msec scan time and it's doing lots of comms.

To help out with online monitoring and editing we followed technote 32963.

In short try setting up your CIP options in RSLinx like this:

 

kolyur

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• Jun 30, 2010

• #6

I posted about a similar problem several years ago:
http://www.plctalk.net/qanda/showthread.php?t=31038

I was never able to solve the problem; Ethernet comms are still ridiculously slow on this particular PLC. Changing the CIP options in RSLinx did not help in my case.

 

jac

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• Jun 30, 2010

• #7

we went down this road yesterday....


http://www.plctalk.net/qanda/showthread.php?p=380558#post380558

I agree with the previous comment. The SLC505 is slow Enet comms' no matter what. Long live the PLC5!

 

JesperMP

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• Jun 30, 2010

• #8

50 ms scantime is still somewhat high. It may affect comms to a degree.

The problem may also be excessive polling of tags from the HMI.
How many HMI tags are there ?
How often are they polled ?
Are the tag addresses grouped together ?
As an experiment, try to remove the HMI completely, and see if it improves the online updates in RSLogix.

 

jac

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• Jun 30, 2010

• #9

The scantime is normal for a large program.... I've had SLC scantimes in excess of 45ms. The SLC uses only one processor for comm's and the program scan compared to the PLC5 what has a separate processor for comm's. Lighten up on the update rates of the HMI tags and be sure the PLC files are contiguous. Try sticking a couple of SVC instructions in between the JSR's to update the comm's more often.


Cheers

 

phinix

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• Jul 1, 2010

• #10

hi jac , what do you mean by "be sure the PLC files are contiguous"

 

phinix

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• Jul 1, 2010

• #11

thanks


many Thanks for your help ,

at the moment the situation has stabilized

after increasing hmi puling time, and rslinks configuration
i got some improvement .

but real change came withe the svc instruction
it did cost me about 1 ms for each svc

still i cant really understand way a similar plc on the same lan with similar io ,rungs, words used , and scan time ,is communicating ok and these do not?!

 

IASAUTO

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• Jul 1, 2010

• #12

Check Comms Servicing Selection bit S:2/15 and Msg Servicing Selection bit S:33/7 in the Processor Status / Chan 1. If S:2/15 is set, clear it and see what happens to your communications speed and scan times.

 

jac

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• Jul 1, 2010

• #13

"hi jac , what do you mean by "be sure the PLC files are contiguous"

It is common practice to have all files->Tags in common files in the PLC.
Example a Reals be F50:XX and Bits B51:X/X etc. That way there is less work to be done to create a enet packet. Sometimes it's bit more work but it is worth it on a large project.

Cheers