Skip to Content

Register Login

Default Header

(header konnte nicht geladen werden)

Navigation

S7-300 outputs unexpectly come on while deleting blocks online

Created by: AUS_MB at: 4/27/2009 3:24 PM (4 Replies)

Rating (0)

Thanks 2

5 Entries

4/27/2009 3:24 PM	Rate (0)
AUS_MB Posts: 45 Rating: (0)	Hi All Today I deleted all online blocks from a CPU-317 2PN/DP. The CPU was in run mode. Immediately after the blocks were deleted several digital outputs came on and stayed on for 1-2 seconds. Some equipment was damaged but it could have been worse. Anyone seen this before? Is it a symptom of a problem or was it simply bad practice to delete all of the online blocks while the CPU is in run mode? Thanks mb
AUS_MB Posts: 45 Rating: (0)
Suggestion To thank Quote Answer

4/27/2009 3:40 PM	Rate (0)
umencho Grandmaster Joined: 3/21/2006 Last visit: 1/4/2026 Posts: 10242 Rating: (1183)	Hello, The question is WHY did you did this? What are the reasons?... Best regards

Suggestion To thank Quote Answer

4/27/2009 3:48 PM	Rate (0)
Sydney Gold Member Joined: 1/4/2008 Last visit: 12/22/2025 Posts: 703 Rating: (98)	Hello, I don't know why some outputs were energized but as you wrote it is a such bad method. If you like to do something like this, the plant should be stopped in the right way firstly, the PLC should be switched to stop mode and then you can make this big things. Regards Sydney

Suggestion To thank Quote Answer

4/28/2009 11:33 AM	Rate (0)
AUS_MB Posts: 45 Rating: (0)	You are both right. It was not a hardware fault and I should have put the CPU into stop. The outputs were energised by the user program. Since the input mapping routine in the user program was deleted first the program responded to the input turning off by actuating outputs. The outputs only remained on for the second it took for the rest of the user program to be deleted
AUS_MB Posts: 45 Rating: (0)
Suggestion To thank Quote Answer
This contribution was helpful to 1 thankful Users Khaled_Ezzat

6/15/2009 3:13 PM	Rate (0)
Yer Posts: 86 Rating: (7)	Hello, Next time you want to to things like this you can built is some protections. First delete the call of the block. Whenn you are sure the block is not called by the user programI think it can be deleted without problems. Second. Be aware if the block set a flag or an output it will stay after delete the call or block. so after deleting set the output in the safe condition by using a fat table. Best regards, Yer
Yer Posts: 86 Rating: (7)
Suggestion To thank Quote Answer
This contribution was helpful to 1 thankful Users dchartier

|

Share this page:

Share this page on...

Follow us on