plc DATA problem

[indra]

Hi, I have plc cpu a2 series "mitsubishi" we have problem with our wrapping machine that use plc data "D66" signal counting from encoder the problem d66 can not stop (reset) that make conveyor running continue. In normal condition should be the paper on conveyor on position, ( ready to wrap ) and stop conveyor ( with make reset/"0" counter to stop conveyr, to make wrapping action. Please help me to trace this "D66" signal which make to reset / zero because i trace the program, like a circle back to this counter data again ( D66 ) I enclosed the capture of the D66 that always counting , never stop that make conveyor over postion and wrapping step can not be done.

[Goody]

What unit are you getting your count from?

[indra]

[nehpets]

I don't know if this helps as I'm only familiar with the fx range. while Y54 is true then the instruction DFRO will be active DFRO reads a 32 bit store of a special function block buffer memory (encoder unit), the special unit address is 'H4' , the buffer memory store is 'K4' , it's transferred to 'D66', and 1 word is read 'K1' [DFRO H4 K4 D66 K1] do you have any information on the encoder module at the PLC (not the encoder itself) I'm not sure but I don't think you need to zero the encoder except maybe to re-reference it at sometime generally you read the value and do comparisons to achieve actions. The value in D66 is a result of the instruction DFRO reading the encoder values. Steve have a look at this AD61 manual Edited May 16, 2011 by nehpets

[Crossbow]

The encoder will never stop counting. It's not designed to. You need to write code to cause it to stop or zero out. Your program is set to read the current encoder value from the module every time Y54 turns on. That's what the DFRO instruction is doing, and it writes a 32-bit value to D66 (and D67). So the only way to make it 'stop' is to stop reading the latest value from the module.