11/27/2019 8:58 PM | |
Joined: 9/8/2008 Last visit: 8/7/2024 Posts: 23 Rating: (0) |
I have the same problem. I use 4 pcs. CPU1211 with CB1241 for Modbus-Master communication with several slaves. I set REQ=1 just only in the next scan after (DONE OR ERROR OR NOT BUSY)=1. Approximately each year one of CPUs goes to state in which all requests result to ERROR=1 and STATUS=81D0. I tried to force REQ=0 for a minute, but without result. Is there any better solution then putting the CPU to STOP and RUN? ------------------------------------------------------------------------------------------ |
Last edited by: Jen_Moderator at: 11/28/2019 11:57:00New subject after splitting |
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12/9/2019 11:53 AM | |
Joined: 9/8/2008 Last visit: 8/7/2024 Posts: 23 Rating: (0) |
Hello, sorry for wrong description. I called a whole part of program with Modbus_Master call only each 1 second, so practically set scan time to 1s. In video you can see, what happened. Resetting STATE to 0 has no effect, but calling Modbus_Comm_Load once resets this error. I also try to check in which circumstances this error occurred. It looks, that communication is blocked permanently with STATUS 81D0 after sequence of results STATUS 81E1-81EA-81D0, but after 81E1-81EA-8387-81D0 is 81D0 received only once a communication continues. Best regards, Mrk. Attachmentmbm_png.zip (125 Downloads) |
Last edited by: MIMR at: 12/17/2019 00:57:46 |
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12/9/2019 3:50 PM | |
Joined: 9/8/2008 Last visit: 8/7/2024 Posts: 23 Rating: (0) |
Hello, here Is the program. But in the video you can see that REQ is set exactly in next scan after DONE or ERROR. On network there is sure any hardware problem. The slave with address 2 always answers with parity, frame or CRC error and may destroys communication with next slave with address 3. I am afraid the Modbus_Master block cannot manage this situation correctly. Now the error occurs about once a day, which corresponds to 1 in 50,000 calls of slave with address 2 Best regards, Mrk. Attachmentmbm65.scl.txt (129 Downloads) |
Last edited by: MIMR at: 12/10/2019 11:38:48Last edited by: MIMR at: 12/10/2019 11:59:02 |
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12/12/2019 9:15 AM | |
Joined: 9/8/2008 Last visit: 8/7/2024 Posts: 23 Rating: (0) |
Hello, here is the trace - DB snapshot with few comments. After each call of Modbus_Master its I/O ware traced. Best regards Mrk. Attachmentx.db.txt (140 Downloads) |
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