Hello,
I am currently working to control
a Control Techniques Drive system via LabView and CanOpen, such that the drive
system acts as a vehicle emulator. So far I’ve been able to read and write
different parameters from LabView to the Control Techniques Drive system
through Service Data Object (SDO) Protocol. However, I would like to
communicate to the test rig using Process Data Object (PDO) Protocol. If I
manually configure the PDO1 from the drive, I can read values stored in it
without a problem, however when it comes to using PDO Write, I don’t get any
error, but I also don’t get any response. One of the default values for the
RxPDO1 includes setting the speed of the motor, so if I want to access that
parameter to write a desired speed in percentage,
- What is the format of the value that LabView needs
to convert to CanOpen format?
- What needs to be connected to CanOpen data in?
- How can I write to different channels stored in one
PDO?
As I go through the CT CanOpen
manual, there seems to be a gap in how to do the mapping for the different
PDOs, and how to access the specific menu and parameter. If I want to configure
different PDO objects beside the first one that can be configured manually, I
have to follow a series of steps which begin by writing enable to the address
of the PDO object i.e. TxPDOB 0x1A01, sub-index 0.
- Is enable in this case a zero value that I need to
write through SDO to this sub-index?
- When setting up a PDO (master-required) do
communication parameters need to be written before enabling that PDO?
- Frames for PDO contain a control bit, is it in this
case parameter 6.43?
I’m attaching what I’ve been
working on so far, plus the CT CanOpen datasheet, and I hope you can point me
in the right direction. To make things a bit easier, I'm also attaching a slight modified
version of the Analogue Output VI (Untitled2.vi), that's found in the CANopen examples
folder. In the drive, there are 4 PDOs, each with 4 TxPDO and 4 RxPDO
channels. The first PDO can be configured directly from the drive, and
that's how I've been able to read parameteres. However, when it comes
to write, that's when the problem comes. With this VI, the first RxPDO
channel is configured to set the speed of the motor (directly
configured in the drive), but I'm not getting any response.
Thanks for your help,
Enrico
