7I96 Plasmac THAC / encoder config question

I am setting up a 7I96 to use with a small plasma cutter. I am trying to confirm the dual THAC setup. Can I use the stock bit file for the 7I96 or do I need one with 2 encoders instead ?

the stock bit file for a 7I96 looks like it has a single quad encoder setup
TB1
pin 27 Quad-A
pin 28 Quad-B
pin 29 Quad-IDX

The Plasmac instructions is based on the 7I76E for the connections
Assuming it is connected to a 7i76e, connect the output to the spindle encoder input:

THCAD +5v to TB3 Pin 6 (+5 VP)
THCAD -5v to TB3 Pin 1 (GND)
THCAD FOUT+ to TB3 Pin 7 (ENC A+)
THCAD FOUT- to TB3 Pin 8 (ENC A-)

For the second encoder it needs a separate bit file that adds another encoder input to read

Thank you for the help
Calvin

calvin.d wrote: I am setting up a 7I96 to use with a small plasma cutter. I am trying to confirm the dual THAC setup. Can I use the stock bit file for the 7I96 or do I need one with 2 encoders instead ?

the stock bit file for a 7I96 looks like it has a single quad encoder setup
TB1
pin 27 Quad-A
pin 28 Quad-B
pin 29 Quad-IDX

The Plasmac instructions is based on the 7I76E for the connections
Assuming it is connected to a 7i76e, connect the output to the spindle encoder input:

THCAD +5v to TB3 Pin 6 (+5 VP)
THCAD -5v to TB3 Pin 1 (GND)
THCAD FOUT+ to TB3 Pin 7 (ENC A+)
THCAD FOUT- to TB3 Pin 8 (ENC A-)

For the second encoder it needs a separate bit file that adds another encoder input to read

Thank you for the help
Calvin

There is a zip file of firmwares on the Mesa site for the 7i96 card. There’s a 7i96dpl.bit (or something very similar, doing this from memory), use the mesaflash guide in the 7i96 manual to flash the firmware on the card. It will give you three Quad-A encoders, which you will use two of them. Then you’ll use the .00 velocity for THC and .01 velocity for ohmic.

Hopefully that makes sense...

yes it does, I was hoping there as a pre made bit file for this

ill give it a try now

Thank you

Missed the connections question, just follow the pin out guide on the 7i96 manual, it’s still ENCA+ and ENCA- for the thc, then you’ll use the ENCB+ and ENCB- for the ohmic, but the firmware will identify it as two QUAD-A’s

Looks like that was exactly what I needed
for anyone in a similar situation

1. get the support software for the 7i96 from the mesa site
2. connect to the board via mesa flash tool
"mesaflash --device 7i96 --addr 10.10.10.10 --reashmid"
will give you the current pinout based on the bit file loaded
3. decompress and find the 7i96dpl.bit file in the support software
4.flash the board
"mesaflash --device 7i96 --addr 10.10.10.10 --write 7i96dpl.bit"
5. power cycle or use mesaflash to reload
6. confirm the new bit file was loaded and the pinout changed
"mesaflash --device 7i96 --addr 10.10.10.10 --reashmid"

This now gives me

TB1
Pin 7 Quad-A
Pin 8 Quad-A
Pin 9 Quad-A

So I now have 3 A channels on 3 separate encoders, these are single ended right so now I am just running

THCAD FOUT+ (THCAD#1) ---> pin 27 Quad-A
THCAD FOUT+ (THCAD#2) ---> pin 28 Quad-A

and I am not connecting THCAD FOUT- to anything right ?
Is it worth while ti look into a bit file that has and A and -A pair for better signal protection ?

C

From the manual

TB2
7 ENCA+
8 ENCA-
10 ENCB+
11 ENCB-

is now really
TB2
Pin 7 ENC0A+
Pin 8 ENC0A-
Pin 10 ENC1A+
Pin 11 ENC1A-


so that maps to
THCAD FOUT+ (THCAD#1) ---> Pin 7 ENC0A+
THCAD FOUT- (THCAD#1) ---> Pin 8 ENC0A-
THCAD FOUT+ (THCAD#2) ---> Pin 10 ENC1A+
THCAD FOUT- (THCAD#2) ---> Pin 11 ENC1A-

C

Yep! Looks like you got it figured out! Thanks for the extra intel for those who come looking.

ok next problem

starting linuxcnc
error
setp requires 2 arguments, 1 given

for this line
"step hm2_[HOSTMOT2](Board).0.encoder.00.velocity

the initial config was made with the 7i96 config tool, I think I am going to convert it and hardcode all off the variables our of the config lines

still trying to figure out why that encoder line is not reading correctly

C

calvin.d wrote: ok next problem

starting linuxcnc
error
setp requires 2 arguments, 1 given

for this line
"step hm2_[HOSTMOT2](Board).0.encoder.00.velocity

the initial config was made with the 7i96 config tool, I think I am going to convert it and hardcode all off the variables our of the config lines

still trying to figure out why that encoder line is not reading correctly

C

There’s an example in the plasmac user guide in section 27, but I think the (board) just needs to be changed to 7i96.

You may be better off using Pncconf and unchecking all the extra options then you don't end up with a lot of unnecessary lines. The encoder velocity line for instance is not need in the hal file but is set later by the Configurator.