SLC 5/04 timer pre

[TrevorD 1]

Hi all

I am brand new to rslogix500

I am a little confused as to the maximum value that can be placed into TON pre and acc. Being 16bits it should be 65535 how ever my current program has 32767 will increasing the value cause a problem. I cant see why you would want to have a negative number in a timer.

Look forward to your reply

Trevor

[Twigums 3]

If the number goes above 32767 a minor fault will occur.  This will throw the processor out of run mode.

 

To recover from the error, you need to make sure the high value is cleared, and then just reset or clear the fault. 

This may only apply to counter and integer registries though.

https://literature.rockwellautomation.com/idc/groups/literature/.../1747-rm001_-en-p.pdf

Checkout page 43 section 2-7

Edited 14 Jun 2019 by Twigums

[TimWilborne 108]

Hi Trevor.  All 16 bit integers in RsLogix 500 are signed integers whether they are allocated to an N7 integer, a counter, timer, or anything else.  You are right, for a timer it doesn't make sense to have a negative value, but for many other PLC functions you can end up with negative numbers. If you need timers greater than 9 hours then you'll need to trigger a counter after a certain time lapse.  I like to use 3600 seconds or one hour.  I've got a video coming out about how to do that.

[TrevorD 1]

Thank you for your reply. 

I will look into using a counter set up or running 2 timers. 

Seems like rslogix500 will take some getting used too.