Counting servo command pulses with FX5U

[LauriM 0]

Hello everyone,

I am controlling a mitsubishi servo amplifier type MR-J4-20A-RJ with a Mitsubishi FX5U PLC. I am using DDRVI instruction to output the pulses to the amp with pulse/sign connection. Servo seems to work as requested, and cumulative pulses in MR configurator make sense.

The problem: I can follow the output pulses and get a "position" from special register SD5502. If i understand it correct, the register sums the pulses output. If drive the servo to other direction, the register keeps adding up the value, not subtracting it. As i am new to mitsubishi, what would be the right way to get the position data? Is it possible to use the special registers for it, or should i just connect the servo to output the cumulative encoder pulses to PLC?

 

Thank you all for your time!