How to communicate with Compax3 via RS232

[Roy_of_Leicester]

Here's the VB6 code I used to change speed:

format_speed = Format(Str(speed_value * 174 / 11), "####0.000000") 'Controls format of sent string, converts to deg per sec at motor

next_buffer = "o1902.1=" & format_speed

Call send

next_buffer = "o1100.3=16643" 'Sets start bit low

Call send

next_buffer = "o1100.3=24835" 'Sets start bit high.

Call send

So..load the next speed into the buffer, then flick the start bit low then high.

Hope this helps

Roy

[davecyli]

Thanks Roy!

That'll let me do some interesting things.

Have you measured the time it takes for the controller to respond to the messege?

You think it's around 10's of ms or 100's?

No probs if you don't know. Just wondering.

Thanks,
Dave

[Roy_of_Leicester]

Hi Dave

It was quite quick, as I remember. I was getting around the whole loop in 30-50ms, and this included reading a strain gauge sensor and a few other things. I guess that a lot of the delay was in the I/O ports and handshaking. Would have been faster if I was using a PLC instead of a Windows XP PC.

Good luck!

Roy

[Mel-D]

Thanks Davecyli....just to confirm what you just said, I have to:

First, command to set to MoveRel mode in Motion Table Row 2:

O1905.2=2

Then, command entry to set table (Pg. 296 in the C3I1T11 manual):

O1904.2=$32

and finally Set Bit code

O1100.3=$6203

correct? In case this does not work and I'm not in free mode, I do I enable the FREE mode  in the Parker Integrated Engineering Tool. Do I do it through the C3manager software? Thanks!

[davecyli]

@Roy,

Yeah I'm running through windows as well.. but that delay should be fine. I'll post my results once I get it working.

@Mel,

That looks correct.

If your controller had a position feedback, you could also do O1905.2=1 for MoveAbs in place of O1905.2=2 for MoveRel.

I just said MoveRel because that worked for me when I didn't have position feedback.

Here is where you choose Free Assignment mode in Parker Integrated Engineering Tool:

And then download to controller.

Good Luck,

Dave

[Jason@WTI]

Mel, in the Parker configuration software (as shown by Dave) check the 'Motion Profile Table' and make sure you have a profile setup on SET#2. Without that, you're not going to move at all.

Regards,

Jason

[Mel-D]

@ Dave and Jason. I really do appreciate the help. What Dave said was right on...I can now move.

Now the next step is to track the position until the target position is reached. My motor has an encoder so if I put the following command sequence:

• Write O 680.5CR to buffer (request current position). I found that object on page 318 of the manual
• Write O 1904.2=$32CR to buffer (Entry to table set). Do I need this?
• Write O 1100.3=$6203CR to buffer (to execute the request, as I'm guessing that's what this command does, but Do I need this?)
• Use the "VISA Read" (to read the buffer and find out what the encoder replied.)

in a while loop and stop the loop when the current position is equal to the target position will that work? Or this should be done differently.

cheers!

[davecyli]

I'm not sure, I haven't done any position tracking. Only velocity,as I'm using my motor in a dyno rig.

In my labview code, I have a separate thread that constantly reads the speed and updates a variable.

You can do the same for position with your first command. O680.5CR

[Mel-D]

Hello,

You guys know if the compax3 has an E-STOP command that will stop the motion in case of an emergency? Also is there a HOMING command? I don't know but the manual doesn't seem to be clear on those. 

[davecyli]

There's definitely a homing command. I've never used it though because, again no encoder.

The homing feature is shown in the status diagram on page 289. 

As for the estop, I have a estop on my rig that i press that shuts power to everything.

The estop feature might be in PIET?

Sorry, I can't be of more help.

-Dave