I know you said your done, but here is a trick, use the holding register instead of the coils. Add the bits together then write it at one time with FC6.
You also could have wrote the following to the Holding Register instead of using Coils. My 7300 works fine like that.
1 = Run in Forward
3 = Run in Reverse
17 = Jog Mode in Forward
19 = Jog Mode in Reverse
The bits are simple Binary,
The first bit is 0 or 1
2nd is 2
3rd is 4
4th is 8
5th is 16
6th is 32
7th is 64
8th is 128
You simply add the values together for the bit combination you want.
For Example: Run Forward is the first bit so writing a 1 to the holding register sets the 1st bit.
Writing a 3 to the holding register sets the first and second bit to ON
Writing a 19 turns on RUN, REVERSE, and JOG
Switched to a Hitachi SJ200 after my original Teco drive failed on me.
There were many frustrating hours spent trying to get this working but I finally figured it out.
Below are the Modbus setup screen & the Brain I'm using to accomplish Forward / Reverse / RPM's in Mach.
Since all it takes is to write to 1 coil for reverse motion that was easy (the second coil defaults to 0 which changes direction to forward)
The hardest part for me was figuring out how to write to two coils at the same time to get forward motion.
Finally dawned on me I could use the same 'Spindle CW on' LED twice to do this .. mapping it once to coil '0' & once to coil '1' .
Once I made that single change in my brain .. it worked perfectly.
RPM's also have to be written to register '0' to work .. because again that's actually the first register.
Hope this helps someone else who's struggling like I did to understand this stuff.