Need a little help

LowerySJ · Jun 1, 2006

I have a project using RSL500 using processor 1200C in which I need to keep an output energized anytime the PLC controller is active, on line and functioning properly. In case of controller failure or power outage, the output needs to de-energize.

Can anyone send some light with this???

Thanks in advance.

bernie_carlton · Jun 1, 2006

Just add an unconditioned rung with the output as an OTE. I'm pretty sure that outputs are only enable in Run mode. But since most controllers are not safety devices there is no way to guarantee the failure mode.

504bloke · Jun 1, 2006

Something like this ?

TConnolly · Jun 1, 2006

I had a machine come in once that was programmed with the following line



MAJOR_ERROR_HALTED

     S:1/13              O:12/15

-------]/[-----------------( )---

 

 

However, 

 

                         O:12/15

---------------------------( )---

 

would have been sufficient.

Red flags went up when I saw that, as the programmer was not grasping something fundamental.  Sure enough, the software proved to be problematic.

504bloke · Jun 1, 2006

MAJOR_ERROR_HALTED

S:1/13 O:12/15
-------]/[-----------------( )---

Ken Moore · Jun 1, 2006

I would make sure this rung was at or near the end of the ladder.

Need a little help

LowerySJ

Member

bernie_carlton

Lifetime Supporting Member + Moderator

504bloke

Lifetime Supporting Member

TConnolly

Lifetime Supporting Member

504bloke

Lifetime Supporting Member

Ken Moore

Lifetime Supporting Member

Similar Topics