Dynomotion

Group: DynoMotion Message: 7754 From: daveymahomh600e Date: 6/23/2013
Subject: KFLOP to Hitachi VFD via Modbus
If a person were to want to connect a KFLOP board to a Hitachi WJ200 VFD, how painful is it to accomplish this with Modbus? Both ends have an RJ connector, so I suspect there is some way to build the missing link. The VFD is supposed to have built-in RS-485 serial communications featuring the Modbus RTU protocol.

Data in the form of start/stop signals and frequency changes would need to be exchanged.

Any thoughts? Suggestions?

Thanks,
David.
Group: DynoMotion Message: 7760 From: Tom Kerekes Date: 6/23/2013
Subject: Re: KFLOP to Hitachi VFD via Modbus
Hi David,

It is certainly doable.  KFLOP only has LVTTL UART signals.  Kanalog converts them to RS232 signals.  If you need RS485 then you would need an adapter.  One thing about Modbus is that there are quite a few pieces to the puzzle.  LVTTL/RS232/455, baud rate, parity, TX/RX wiring, ModBus Register Ranges, protocol, etc...  Everything needs to be correct for it to work.  If you just connect it up without testing intermediate points then it can be be frustrating to make work.  See the ModBus Examples in the in the C Programs/RS232/ModBud directory.

Regards
TK


Group: DynoMotion Message: 7761 From: David Stevenson Date: 6/23/2013
Subject: Re: KFLOP to Hitachi VFD via Modbus

Hi Tom,
 
I didn't expect it would be easy. I'll check and see exactly what the signal requirements are for the VFD.
 
Thanks,
David.
 
-----Original Message-----
From: DynoMotion@yahoogroups.com [mailto:DynoMotion@yahoogroups.com]On Behalf Of Tom Kerekes
Sent: Sunday, June 23, 2013 8:18 PM
To: DynoMotion@yahoogroups.com
Subject: Re: [DynoMotion] KFLOP to Hitachi VFD via Modbus

 

Hi David,

It is certainly doable.  KFLOP only has LVTTL UART signals.  Kanalog converts them to RS232 signals.  If you need RS485 then you would need an adapter.  One thing about Modbus is that there are quite a few pieces to the puzzle.  LVTTL/RS232/455, baud rate, parity, TX/RX wiring, ModBus Register Ranges, protocol, etc...  Everything needs to be correct for it to work.  If you just connect it up without testing intermediate points then it can be be frustrating to make work.  See the ModBus Examples in the in the C Programs/RS232/ModBud directory.

Regards
TK