OTE instruction

[mmd604 1]

Can you not force a OTE instuction when you are in remote program mode?

[panic mode 246]

what PLC?

[mmd604 1]

1756(5571)  5000 suite.   I have been trying to force a solenoid valve and when I force it from the controller tags nothing happens it say ON and I apply forces but nothing happens.  I go back and look at the controller tags and the force mask says 1 but the value remains 0........ I know its gonna be some thing so simple

[Armadillo852 25]

To clarify, you are in remote mode and not program mode?

 

Edited 17 Apr 2020 by Armadillo852

[mmd604 1]

yes Armadillo852 I was in remote program

[ElectronGuru 81]

When you're in program mode, whether "Program" or "Remote Program", the code is not being scanned. So while you can add and remove forces in either program mode, those forces won't take effect until you go back to "Run" or "Remote Run".  

It might be helpful to note that in ladder logic, when you're looking at the OTE on the rung it will be displayed according to rung logic, not the force. So if the rung is false and you've force the OTE to on, the red "ON" below the OTE instruction is your indication that the output should be on. This is because output instructions pass through logic before the force mask. (The opposite is true for forced inputs; they're displayed on the rung according to the forced condition, not logic).

Edited 17 Apr 2020 by ElectronGuru

[mmd604 1]

I knew it would something simply.  I am confident you are right with clarify tomorrow thanks !

Edited 17 Apr 2020 by mmd604

[Armadillo852 25]

11 hours ago, mmd604 said:

yes Armadillo852 I was in remote program

There you go then! Nothing executes in program mode.

[BobLfoot 301]

To clarify just a bit further.  AB PLC work with a Data Table.  Logic Reads & Writes the Data Table, Forces affect the Data Table. and the running CPU transfers the Data Table to it's mapped real world I/O.  In the SLC500 and PLC5 family there is only one CPU so I/O updates happen between scans of logic.  The ControlLogix and CompactLogix families have multiple CPUs.  So the Real World I/O is updated while the progam is scanning.  But here again still must be in RUN or REMOTE RUN.