Hi guys

I have a west 4400 temperature controller which controls the heating and cooling of a process last week the whole controller went a little haywire and lost all its memory and set points. After much trial and error i have finally gotten it back to where it needs to be, well almost. The problem i have now is that i cannot run the controller from the external start button on the panel. when the controller is manual and i start the process through the button on it the whole process works fine. but as soon as i go into auto and hit the start button on the mains panel the controller goes into hold mode as if it is waiting on another condition to happen elsewhere but there is no other alarms or resets that need to be done. This is run by a siemens Logo plc. i have attached drawings of the function block diagram which i am not too familiar with at all as im more used to ladder logic along with a schematic of the controls. listed below is the process in short. As said no other conditions need to be met as far as i can see and if i change back to manual on the controller the whole process starts not a problem.


When the start button is pressed the controller heats up to 110 degrees
when the 110 degrees is reached an audible alarm sounds and it is silenced through a rest/mute alarm button on mains panel (this works fine no problem)

Then there are some ingredients added which causes the temp to drop and when all ingredients are added the batch stage advance button is pressed and it heats the mix up to 100 degrees. When the 100 degrees is reached it is held at that temp for 10 minutes and then it begins to cool down to 80 degrees. When this is done the mix is complete and the controller reads END which it should. The operator then empties the tank turns a key which resets the controller (when in auto) and the whole same process begins again.

All of the above works fine bar the programme being held in auto when the start button is pressed as said too i cannot see or find anything that causes the hold to stay on. Sorry for the mouthfull guys but i aint sure of the function block diagram no real experience with them to be honest. Any feedback would be great

 

It has been a while, but IIRC you monitor the status of the rungs, if so, is there any rung that looks like it should be made to complete the task?
Max.

 

Hi Max

I do not have the software or program for this so i cannot check exactly whats going on. the function block chart is the only info i could find on it and who can be sure the program hadnt been changed since that was made up

 

If it has been changed then you definitely need the S/W.
Max.

 

Yeah my next quest will be to get SW. If i do could it be possible that i could convert or view the program in ladder format as it would make it more tangible for me to understand. Is such a thing possible with the Siemens SW im mostly familiar with Mitsubishi myself

Thanks

 

I use Mitsubishi extensively also.
But IIRC you cannot convert to ladder, some smart relays you can.
Max.