Engineer story sharing(4)

The original project was made by Mitsubishi. After changing to the domestic PLC, the program is basically unchanged, that is, the number of pulses of the absolute position command of DDRVA is one D8170, one is D8140, and the end of the detection displacement is different.


After the program is downloaded to the PLC, the test is performed. As a result, Y0 and Y4 have no action. Try Mitsubishi's problem!


Start looking for reasons:


My program is automatically adopted


LD M10


DDRVA D10 D20 Y0 Y4 to perform.


Manual is performed by DPLSY.


DPLSY K10 K0 Y0 Mitsubishi's implementation is no problem.


Why can't domestic PLCs work?


I will only write the above command test alone, it is still possible for Mitsubishi, and the domestic PLC can't.


There is no way to write DDRVA D10 D20 Y0 Y4 alone to test the domestic PLC is good, I add DPLSY K10 K0 Y0 results before and after the instruction is not executed.


Trying DPLSY K10 K0 Y0 alone is also not working, and Mitsubishi is moving.


It is possible to change the instruction to: DPLSY K10 K10000 Y0 to test the movement of the domestic PLC. Then add DDRVA D10 D20 Y0 Y4 to test, the result is only DPLSY action, DDRVA does not work.


The same procedure Mitsubishi is moving, can't domestic PLCs use these two commands at the same time.


In order to complete the project, I can only change the program without DPLSY, and the machine can finally move.


This pit is self-digging. In order to reduce the cost, I also use the domestic PLC for the first time, but also to understand.


I can't tell the brand of domestic PLC here, I support domestic products.