9/30/2020 10:18 PM | |
Joined: 9/27/2006 Last visit: 10/12/2024 Posts: 12287 Rating: (2685)
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Hello Qasim; If you have lost contact with the redundant CPUs, you will have to rely on the diagnostic LEDs to find basic information on the problems that the PLC detects. Does the stand-by CPU in rack 1 exhibit the same combination of diagnostic LEDs? By the way, is this a newly installed system that started up with these LEDs, or was it a running system that suddenly crashed and gave you these signals? The screenshot below is taken from the Fault-tolerant S7-400H system manual, Ch. 5, Assembly of a CPU 41xH:: https://support.industry.siemens.com/cs/ww/en/view/82478488 Your active LEDs show us that the CPU you display in your screenshot is presently the redundant master, is in RUN mode, exhibits an external fault (not from the CPU and has lost a DP master system (probably linked to the BUSF LED on the CP 443-5 EXT). You do not seem to have a loss of redundancy problem (the IFMxF LEDs are both off) and you show no faults on your CPU integrated ports (BUSF is off). On the CP 443-5 EXT, the combination of LEDs EXTF ON and BUSF LED Flashing indicates that the module is in “RUN; however there are on problems on the DP line (DP slave not in data transfer or not accessible)” See the CP 3443-5 EXT manual Part B, Ch 2: https://support.industry.siemens.com/cs/ww/en/view/8777196 Very likely (from my experience, anyway) the basic problem of your CPUs appears to come from the loss of a DP slave on the network controlled by the CP 443-5 EXT. Since you have lost communications with the PLC, you must look for the faulty module by physically visiting all the slaves and finding which one(s) shine their own diagnostic LEDs, a BF most probably. Once you have located the faulty slave, check all physical connections to Profibus (cable, connector, termination position on the connector), the status of all red LEDs on the connected modules (if it is a IM 153-2, for example, look for defective modules on the rack), and tell us what you find. Hope this helps, |
Last edited by: dchartier at: 09/30/2020 22:19:27 |
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10/1/2020 12:44 PM | |
Joined: 4/26/2011 Last visit: 12/22/2023 Posts: 25 Rating: (0) |
Dear Daniel & Sandy, Thanks for prompt reply. @ Daniel: Does the stand-by CPU in rack 1 exhibit the same combination of diagnostic LEDs? "Rack 0 CPU LED Status: EXTF: ON / REDF: ON / RUN: ON / MSTR: ON / RACK0: ON / RACK1: OFF". "Rack 0 CP443-5 EXT LED Status: EXTF: ON / BUSF: FLASHING / RUN: ON". "Rack 1 CPU LED Status: EXTF: ON / REDF: ON / RUN: ON / MSTR: OFF / RACK0: OFF / RACK1:ON". "Rack 1 CP443-5 EXT LED Status: EXTF: OFF / BUSF: OFF / RUN: ON". Is this a newly installed system that started up with these LEDs, or was it a running system that suddenly crashed and gave you these signals? NO it was running since Long time and suddenly crashed. It has been observed that all All IO racks IM 153-2 Module related to Rack 0 CPU are in Active except one. Only one IO Rack IM 153-2 Module related to Rack 1 CPU is active. I switched OFF Power supply of active IM 153-2 Module to switch it to other IM 153-2 Module then Rack 0 related Module become active. But when I again Power ON IM 153-2 Module related to Rack 1 then after booting it become active. As per your remarks I think IM 153-2 Module related to Rack 0 CPU may Fault and need replacement (But there is no any Fault LED is ON). Would please explain If both CPUs are healthy then why I am unable to connect or go online. See attachment AttachmentCPU Redundancy Loss and Communication Issue-4.pdf (351 Downloads) |
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