I have a problem with the stepper motors in a project. The stepper motors have already worked and moved to the correct positions/angles (all axes are round axes). This worked both in the simulation and in reality.
Then I extended the setup and added a frequency converter, which I programmed. I did not change the program/configuration of the stepper motors. In the simulation, everything works as it should. However, when I test it on the real hardware, the stepper motors move significantly too far. For example: I give the command to move the stepper motor from position 0° to 90° (MoveAbsolute). According to the position value (MpAxisBasic.position), the stepper motor is at 90°. In reality, however, it rotates almost a full turn, about 350°. There is no transmission or anything else set.
Old programs that worked and moved to the correct position no longer work either. The same problem occurs. Unfortunately, I am at a loss.
The attached images show the axis configuration and the configuration of the stepper motor card.
Make sure to check if the stepper control task runs in the same cycle time as your X2X and PLK cycle time (or only X2X if the module is next to the CPU). So if X2X cycle time is 2000µs, your task should also run in 2000µs. If your module is operated on a powerlink BC, check both the PLK cycle time as well as the X2X cycle of your BC.
Thanks for your response! I’ve now tried it with various time settings, but unfortunately, nothing has changed.
What I forgot to mention earlier: The problem also occurs when I work with mappCockpit, so completely without a program running in the background. The modules are next to the CPU.
have you checked your motor parameters? You, or Automation Studio, may have inadvertently changed the motor parameters steps/revolution, Units at load, …
I use the same stepper module but without Mapp technology. Here is a screenshot of one of my configurations. The motor parameterisation is in a configuration object, and can be edited in the Logical View. As i know these values are used for controlling the motor. Sometimes AS causes some chaos when transfering edited values from the modul configuration to the apt and ax tables.
As Jan suggested the obvious cause is the timing setting.
See B&R Online Help
What is your hardware setup?
Is the stepper interface card placed in a X20BC0083 powerlink bus coupler ?
If so, the X2X cycle time from the X20BC0083 must also be defined with the same time as cyclic#1.
