I have being trying to get the Hitachi SJ200 VFD working with ModBus and a Spindle.
I have the unit working with no problems with the keypad, start stop the spindle and any speed set with the pot.
Now if I connect it by ModBus with in Mach3 Config ModBus the <Test ModBus> I'm able to write and read both Coils and Holding Registers with no
problems except when issue the coil 0001h Run command and the 0002h Direction Command the VFD goes into Alarm mode. and needs to be reset to clear the Alarm code.
This topic is getting spread out across a few threads. However my post relates particularly to Paul's post above.
I admit I might be confused but it seems to me that there is some inconsistency with register/coil numbering. This issue of triggering a alarm is related, I believe.
The Hitachi manual says the following,
List of coil numbers,
0000h - Reserved
0001h - Run Command
0002h - FW/REV Command
0003h - External Trip (alarm mode)
But when I enter the coil data in this manner in the "Test Modbus" dilalogue it must be entered as shown in the picture below, CoilNumbers.jpg
This to my mind does not align with the Hitachi manual.
So what this means is, when you send a "1" to the third coil in the list, thinking that you are sending a direction command, you are actually sending an external trip command.
Greg