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Is that true that the 20d status can''t be reset until PLC is rebooted?
Created by: usfilter1 at: 9/29/2010 1:14 AM (2 Replies)
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| 9/29/2010 1:14 AM | |
Joined: 5/26/2010 Last visit: 1/9/2012 Posts: 6 Rating:
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We're using a S7-317 as a communication master polling 16 S7-200 RTUs through Ethernet radios(317 uses onboard Ethernet port, 200 uses CP-243). We defined 16 connections in NetPro and all are OK/connected after reboot. 317 normally triggers GETblock one by one(e.g. every2 seconds) and triggers PUT block(s) under certain conditions. Originally wehad 1 GET block and 3 PUT block per RTU anddidn't use Enable(EN) bit of GET/PUT(always enabled).All 16 GETs were OKbut we got Error status of 0x14(20d) for PUT blocks of RTU 8 and higher. Error status couldn't be reset until we rebooted 317. Then we added trigger bit(used for REQ) as enable bit for those PUT blocks and seemed to be able to write to all 16 RTUs successfully. Further tests showed that if we trigger a single write for each RTU fast enough(e.g every 3 seconds), we saw the 0x14 error status again on RTU 8 or higher. Now we added trigger bit as enable bit for those GET block as well and lookslike the only way togenerate the 0x14 error is to trigger more than one PUT block of a RTU at the same time and do that one by one for more than 7 RTUs(we've tried to wait 20 seconds between RTUs). Again once thatstatus is ON, it can't be cleared until a 317 reboot(can't write to that RTU anymore w/o a reboot). We're planning to combine those 3 PUT blocksinto one. We did some research and believe the error means "Maximum number of parallel jobs/instances exceeded". Based on Siemens doc(https://support.automation.siemens.com/WW/llisapi.dll?func=cslib.csinfo&objId=22385333&ehbid=15364953&query=CP+343%2DIT+email&load=treecontent&lang=en&siteid=csius&aktprim=0&objaction=csview&extranet=standard&viewreg=WW), "If this number(16) of parallel jobs is exceeded, these jobs are permanently closed with an error and the status=20d" Several questions: [schnippschnapp] other questions are splitted to What's the meaning of parallel jobs?. Is there anyway to see how many parallel jobs running on the PLC?. Is a job active when a GET/PUT block is enabled or when it''s triggered? . Is that true that the 20d status can't be reset until PLC is rebooted? Is that the meaning of "permanently closed "? If so, why it was designed this way? This is the 1st time we use S7 PLCs on a telemetry job and we've done many jobs using other PLCs(AB, Modicon...). Maybe we're not programming it per Siemens recommendations/rules. If someone could shed some light on it I'd really appreciate it. |
Last edited by: O_Moderator at: 9/30/2010 1:16 PMnew subject after splitting |
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| 10/8/2010 3:17 PM | |
Joined: 12/9/2009 Last visit: 4/18/2024 Posts: 156 Rating:
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Hello, in the following article you can find some information about the number of communication jobs may be used simultaneously in an S7-300 CPU for S7 communication. http://support.automation.siemens.com/WW/view/en/18363371 Here is a sample programm for the programming of the communication blocks FB14 "GET" and FB15 "PUT". These functionsare asynchronous and can last several cycles. Continuous activation of the function block without waiting for the end of the active job can cause a communication overload. http://support.automation.siemens.com/WW/view/en/18610307 Best regards Little Holmes |
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