Good afternoon everyone.  I have two Altivar 12 Variable Frequency Drives.  I am trying to communicate to one of the drives via Mach 3.

I connected to my drive using the serial communication.  The drive is Modbus 485 Serial, and I'm using a RS232 to RS485 converter.

I was able to connect to the drive using both the SoMove software to program the drives, and was able to both read and write to and from the drive using Mach 3 and the test Modbus screen.  I set it up to start with using the serial configuration and not using plugins.  I wanted to try the simplest configuration possible.

I'm wondering if anyone has had any luck to write any commands to the drive.  I was not able to send any commands or any speed settings.

The drive has communication words, NC1 - NC4 and NM1 - NM4, addresses 12761 - 12764 and 12741 - 12744 respectively.  I can read and write to all the NC1 - NC4 words, and read from all the NM1 - NM4 words.  Nothing happens when I write to the NC1 - NC4 words.

Looking at the configuration of the drive, setting parameter Fr1 to ndb should set it to Modbus.  Doing this disabled my terminal strip and wouldn't allow me to start the drive with my pushbuttons.  I then set CHCF to SEP which should allow separate reference and command, which should have allowed the drive to be started from the pushbuttons.  It didn't work.

Parameter Cd1 was set to tEr which is terminal and should allow the drive to start from the push buttons, but it didn't work.  I reset Fr1 back to All which should have put reference back to analog input 1, and I could now start the drive from the push buttons.

I'm going to do some more studying.  I was hoping someone may have figured this out and could help me understand what I'm missing.

My goal is to first be able to start the drive from the pushbuttons and let Mach 3 control the speed.  If this works, I will try to start, stop and reverse the drive as well as set the spindle speed from Mach 3 via Modbus.

Thanks
TeaMan

Teaman,

   I don't know about your drive, but "most" drives, it is one or the other for control, usually Modbus OR Di/Do, with the exception of the Stop button on the drive panel that will usually work no matter how your configured. On some drives you can set the speed reference independently of the control source selection, see your drives docs.

   If you want to have the best of both worlds, i.e. use the external Di/Do and speed control externally and have it also controlled by M3,
then: It would be best for you to get an external Modbus device like Peters ModIO(it does 485), and interface your external buttons/and analog controls to it, then interface it through modbus to to Mach3, note, you will need to write some code that will take into account to be able to enable or disable the external Analog pot, verses, machs SSOVR slider, etc. You would need to do that code in the Macropump or a plugin, it could be done through Brains but, would probably be only used here to bring in/out the data to the modbus.
I would HIGHLY recommend you use the Serial Plugin modbus since you can independently address different ranges of addresses/function groups.

Scott

Thanks Scott. finally got it to talk.  Now on to macro pumps or brains to encorporate it into Mach3.  I posted under brains to see if anyone had any examples.  I now have a lot to learn and absorb.

Thanks again.
TeaMan