Umi 7764 can I use a second axis to control the motor?

[Uli21]

Hi,

I am using the UMI 7764 Box to control a stepper motor (until now without any feedback). Now we are going to instal an encoder for feedback conditions. I installed it at a second axis, because the first is used. Can I use the second one for the encoder and do I can control the motor (first axis) than? Or do I need both on one axis?

Gradeful for any help.

[Jochen]

By default MAX assigns motion resources with matching numbers to the axes. That means, if you configure an encoder as a feedback resource for an axis, MAX will assign Encoder 1 to Axis 1, Encoder 2 to Axis 2 and so on.

In fact this is the recommended way to assign motion resources, as it makes cabling and troubleshooting more intuitive. If there is a strong need to change the resource assignment, you can do this in your application by calling "Configure Axis Resources". With this vi or function call you can create user-defined resource assignments, but again, it's not recommended unless there is a really good reason why to do that.

Kind regards,

Johen

[Uli21]

Hi Jochen,

thanks for the quick answer.

Just want to be sure I understand you correctly. The encoder can be on the, so called axis 2 and the motor on axis 1. And there will be no problem to control the motor with the encoder. Is that right? The axis are defind by the MAX and if I need it I can use the VI you named to give both the same axis, but it isn't really necessary.

Regards

Uli 

[Jochen]

You only can assign one encoder as the primary feedback resource to one axis. That means if you configure an encoder as the primary feedback resource for Axis 1 in MAX, you will see Encoder 1 getting assigned to the axis. If you assign Encoder 2 as the primary feedback resource for Axis 1 in LabVIEW, Encoder 1 will be replaced by Encoder 2. In this case Encoder 1 isn't assigned to an axis anymore, but of course you still can read it with Read Encoder Position.

But again, don't do that just for your convenience. If someone else will have to troubleshoot your system later, it's quite confusing if the encoder numbers don't match the axis numbers. Better change the cabling.

Jochen