Machsupport Forum

Mach Discussion => Mach4 General Discussion => Topic started by: TTalma on January 11, 2019, 10:48:45 AM

Title: Is there an advantage to using modbus VS wires to VFD?
Post by: TTalma on January 11, 2019, 10:48:45 AM
Like the title says is there an advantage to using Modbus to talk to your VFD? I just purchased an Delta MS300 VFD. Reading through the manual it talks about using Modbus to talk to the controller.

I've never looked in to this, so I don't really know anything about it.

So I am wondering if I set up Modbus communication what advantages does it have over direct wiring. Can I get speed feedback, better control of the VFD? What amount of effort is required to set it up. (I am a software engineer so some programming doesn't bother me).

All I currently have connected to my unit is 0v-10v speed input, fwd/rev, spindle at speed, spindle at stop.

Thanks!
Title: Re: Is there an advantage to using modbus VS wires to VFD?
Post by: Steve Stallings on January 11, 2019, 11:11:20 AM
MODBUS can be more powerful if you need more than basic speed/FWD/REV controls.

MODBUS setup will usually be more complex, especially if no one else has an example
of how your VFD control was implemented.

An analog voltage VFD interface requires a PWM to analog conversion hardware device,
which I gather that you already have.

MODBUS requires a USB to serial RS-485 unless your VFD has an Ethernet-TCP feature.
This feature is an option card for the MS300.

Features like speed feedback and advanced control features are VFD dependent and
will require someone to develop the configuration and/or scripts to implement them
in Mach4.