×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Hi guys, I am working at

Hi guys, I am working at

Hi guys, I am working at

(OP)
Hi guys,
I am working at power plant and we are using modicon quantum tsx plc to control and monitor the generators,i notice if we shut the generator down for maintenance and then try starting it after we have problems like sensor not reading, start signal not going trough,so the plant technician normally just turn the power off for a few seconds and then everything work fine ,can anyone explain this to me thanks.

RE: Hi guys, I am working at

And you don't think that the massive surges and whatnot that accompany a generator shutdown and restart might have a deleterious effect on an itty bitty PLC? Not to mention getting out of sync with the generator?

TTFN
FAQ731-376: Eng-Tips.com Forum Policies

RE: Hi guys, I am working at

(OP)
I think you misunderstand what i am saying they don't turn the power off to the plc while the generator is running, they turn the power off before starting and try to reset the plc.
P.S we can't shut down generator so we are controlling the grid.

RE: Hi guys, I am working at

I would look into what the PLC is doing during first scan. I know some processors require some initilization procedure at first scan. Maybe when you go to estop or some standby function on the processor that this initilization on the cards is wiped out or corrupted. Another possible cause, your probably shutting down remote racks and such and the network cant reset based on this happening, since a lot of power plant archetecture is distributed IO systems tied to the PLC.

RE: Hi guys, I am working at

Is the sequence of events ALWAYS the same? What about the timing?

There are only about 3 possibilities:
> the PLC is messing with you and just wants more attention
> the PLC has intermittent boot problems and repeatedly resetting it will eventually get it into the correct startup mode
> the PLC is dependent on something else that takes longer to boot.

TTFN
FAQ731-376: Eng-Tips.com Forum Policies

RE: Hi guys, I am working at

In a PLC. It's got retentive memory if you turn Plc power off for a few seconds, then you might be able to reset the value of those things. Another reason I think is possible is that the plc diagram is faulty... Just a guess.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources