Hello everyone, first of all I apologise for my level of English.

I have been trying for several weeks to run 3 V90 servos via modbus RTU with a S7-1200 plc and CM1241 RS422/485 card using a cable with its terminating and initial resistors with db9 connector.

I have followed the example 109480267:

(https://support.industry.siemens.com/cs/es/en/view/109480267)

to the letter and after many problems I have managed to communicate with the engines. The main problem is that I can't get the motor to turn, when I send the run command via 16#041F the servo is activated but it turns very, very slowly, it takes about 5 minutes to make 1 turn.

No matter what speed you set in "ratedMotorSpeed" and "SpeedSetpoint", the servo always turns equally slow. The speed is always 0, I have configured accelerations and checked all servo parameters.

I attach some screenshots to see if they can help you understand my problem.

0_Einstein

Have you thought about setting Control Mode input to TRUE?

 Changing the control mode to true only changes from IPOS mode to S mode, I have tried in both modes and the result is the same, the servo turns at 0.00X rpm.

I have realised that there is a problem in the MDI sending because when I launch the trigger I lose the communication (the loop stays in the MDI sending state).

Is V-Assistant still connected (and possibly in control) of the V90 when the PLC sends the run command and speed setpoint?  Perhaps the run command is getting through from the PLC (and why it moves at all) but the setpoint is not scaled correctly, or not being sent to the correct place?

vvicente

0_Einstein

Have you thought about setting Control Mode input to TRUE?

 Changing the control mode to true only changes from IPOS mode to S mode, I have tried in both modes and the result is the same, the servo turns at 0.00X rpm.

I have realised that there is a problem in the MDI sending because when I launch the trigger I lose the communication (the loop stays in the MDI sending state).

The thing is that from the V-assistance I have given the MDI parameters and from the PLC I have given the run command and it turns again but very slow (0.00Xrpm).

0_Einstein

Is V-Assistant still connected (and possibly in control) of the V90 when the PLC sends the run command and speed setpoint?  Perhaps the run command is getting through from the PLC (and why it moves at all) but the setpoint is not scaled correctly, or not being sent to the correct place?

vvicente

0_Einstein

Have you thought about setting Control Mode input to TRUE?

 Changing the control mode to true only changes from IPOS mode to S mode, I have tried in both modes and the result is the same, the servo turns at 0.00X rpm.

I have realised that there is a problem in the MDI sending because when I launch the trigger I lose the communication (the loop stays in the MDI sending state).

The thing is that from the V-assistance I have given the MDI parameters and from the PLC I have given the run command and it turns again but very slow (0.00Xrpm).

 

 I have tried with the servo connected and disconnected to the V-assistant and the same thing happens. I have checked from the V-assistant and I receive correctly the PZD with the right values... I must be forgetting something silly that doesn't let me go forward.

After several attempts I managed to get it to work in SPEED mode, giving it the rpm setpoint.
The problem is still that in IPOS mode I can't get it to rotate to position X at a normal speed, it goes very, very slowly (around 0.1 rpm).

I don't know what to try anymore, I'm desperate because it's supposed to be something that should be working well but it's not....