Power Up "ON" Time

[Swervomotor]

Is there any way to determine at what point the ladder logic starts running after power on?  We experience a pretty long Power up before the screen get past the boot stuff but when does the ladder start running?

I have an application that needs a somewhat short power up time for the ladder to start scanning and updating outputs.

 

-Swervo

[Flex727]

Not sure how it would be possible to time that within the PLC, but you could certainly add a ladder rung with an unused digital output triggered by SB 2 and use an external timer to time the power-on to output-on interval.

[Swervomotor]

Great idea,  I will try this with a "heavy" program and try to get a worst case scenario benchmark.  The application would be simple at first but probably grow in complexity as they tend to. 

-Swervo

[Flex727]

3 hours ago, Flex727 said:

an unused digital output triggered by SB 2

Actually, forget SB 2. Just hang the Output coil on the left rail - that way the output will stay on and will be easier to see.

[Ausman]

Swervo, you seem to be transitioning to Unistream, but maybe you could stick with a simple Vision for this that the Unistream system talks to.  The 130s I use get going quickly on very complex programs.  I've never timed them, but it would only be a few seconds at most.

cheers, Aus

[Flex727]

15 hours ago, Ausman said:

Swervo, you seem to be transitioning to Unistream

I forgot which forum I was in when I originally answered, though the answer is essentially the same. I will say that I understand Swervo's concern - UniStreams take a LOOONG time to boot up.

[Swervomotor]

I use the Unistreams quite a bit and have never used the vision. The Unistream takes 10-15 seconds usually for the screen to pop up but was wondering when the ladder actually started. I have a couple 7" unistream for another project I'm going to test the up time with, this is is a battery powered application that would need to start running ladder within a few seconds of power on.  It would be awesome if Unistream had a "sleep" mode that could be "woken" with an input.  The Vision sounds like it may be a better fit for this application, I'm just spoiled with all the functionality of the unistream. 

I'm going to tie in an output directly to the power rail and test in the next couple of weeks. Will update with an answer then,

 

-Swervo

[Flex727]

43 minutes ago, Swervomotor said:

Unistream takes 10-15 seconds usually for the screen to pop up

Which screen are you referring? In my experience it takes 1-2 minutes to get the initial programmed HMI screen to appear.

[Ausman]

Sorry Swervo, confusing you with Visco!  But the 130 idea still very valid.  In fact, your first Vision program could be your timer test!

cheers, Aus