Host Engineering Forum

General Category => Do-more CPUs and Do-more Designer Software => Topic started by: Garyhlucas on April 17, 2015, 05:51:44 PM

Title: Do-more control of a VFD via Modbus RS-485 adapter
Post by: Garyhlucas on April 17, 2015, 05:51:44 PM

I need to control 5 Hitachi WJ200 VFD drives via Modbus.  I want to do it this way primarily because I am also interested in getting data back from the drive, specifically power usage. I am also interested in reducing wiring time as we intend to build a lot of these systems. I've got the Ethernet to RS-485 adapter and the multidrop board as well.  The problem is I am a newbie to Modbus and the learning curve is killing me right now.  Has anyone got some sample code of how to do this in Do-More? I've been reading the manuals but it isn't sinking in too quickly at the moment.

Thanks

Title: Re: Do-more control of a VFD via Modbus RS-485 adapter
Post by: DLTimmons on April 17, 2015, 06:29:49 PM

I use a H2-SERIO-4 card that has a RS-485 Port on the card. Then use MWX and MRX to a gang of GS2 and GS3 drives.

Title: Re: Do-more control of a VFD via Modbus RS-485 adapter
Post by: MikeS on April 20, 2015, 09:25:54 AM

is the "Ethernet to RS-485 adapter" the MB-Gateway from Automationdirect? or is that a Hitachi part?

is the "multidrop board" a Hitachi part?

The Modbus work in Do-more Designer will be generally the same with either Ethernet Comm or Serial 485 comm, the addressing of the slaves being the main difference.

Title: Re: Do-more control of a VFD via Modbus RS-485 adapter
Post by: Garyhlucas on April 20, 2015, 06:58:46 PM

The adapter is the AD unit, as is the multi drop board. Hoping it will work with the Hitachi drives.  I've been trying to get my head around the modbus communications method of controlling drives. I see I have a lot to learn!