Can A Modbus control a.........

[TT350]

Good morning guys.

Can A Modbus control a stepper driver and still
take on 30 I/O’s ?

I was looking at Automation Direct Modbus’
and there’s a lot to choose from do you guys
have a model that you prefer?     

[Chaoticone]

TT350, you can control step and direction as well as 30 I/o thru Mach but don't think you want to control the stepper driver thru modus. If you can, tell us more about your setup, how it will be used, ect.

Brett

[Peter Homann]

Hi,

 The answer is yes and no....

Some PLCs have Stepper motor controllers in them. They usually have a trajectory planner in them, so you set it up to do so many steps or move this distance. The PLC then issues steps including the necessary acceleration and de-acceleration ramping profile.  This feature is useful for controlling tool changer steppers etc.

As to controlling motion axis steppers for Mah3 axis, no you cannot use a PLC, as Mach generates the timing pulses itself. It does not have the capability to control a stepper motor via a PLC. To have mach3 control a stepper via an external device you would need to use a Smooth Stepper or similar motion control device, as these synchronise the movement across all axes.

Cheers,

Peter.

[TT350]

I'm building and ATC for my mill.
My brake out board will do 4 axes and i'm useing them.
I need to control a stepper for the ATC.

[TT350]

What would you guys use?

[Hood]

Get a second parallel port and a breakout or get a SmoothStepper and a breakout. With either you could choose not to use a breakout but..... well there are arguements for and against.
Hood

[Perfo]

It's an easy job and fairly cheap to stick another parallel port in. If you are happy with the performance of your four axis already then this would probably be the simplest way forward.

[TT350]

If I use a smooth stepper and a brakeout board do I still use a PLC?
I'm going to use switches to confirm movements and tell Mach and or a PLC or what ever
you guys suggest to command the next move.

[Hood]

Depends how may Inputs/Outputs you would need, if its more than a second port would give you then yes you would need something like the ModIO or a PLC or........

Hood

[poppabear]

Not in the way you think.............  I run Two Servos, from an ADC DL06 and the modbus controls them, but they are not integrated with Machs motion planner at all. I use them to run an ATC. You can send movement values to a register in a CTRIO module (one CTRIO module will control ONE Stepper or Servo that the drive will take Step and direction.  The down side is you will have to track absolute since the CTRIO only does incremental.

I use mine for my Read-a-head swap-arm ATC, This gets tool changes down to about 2-3 seconds, also buy having intellegent IO like a PLC, you can move all your M6 processes to it and it will handle the tool change. I.e. you send out a tool change command, and what tool, the PLC does the rest, once the initial tool is changed, It sends an Im done to mach, mach will continue machining, meanwhile the PLC rotates to the next tool and gets it independant of mach.

You cant do that if you use one of your motion axis for your ATC since Mach will tie up until that axis is done.

Unless, high end top speed ATC is a absoulte priority for you, it is much, much, much easier just to run the ATC as an Axis, and do a traditional simple rotary axis.

Scott