Pin assignments on 7I76E

Hi,
I have just received a 7I76E to switch from mach3, and testing the card outputs with the oscilloscope I've managed to make is work on my 3 axis. But I really don't understand the logic behind the pin assignment numbers.

On the manual page 8, I can read for TB2 :
PIN SIGNAL
1 GND
2 STEP0-
3 STEP0+
4 DIR0-
5 DIR0+
6 +5VP
7 GND
8 STEP1-
9 STEP1+
10 DIR1-
11 DIR1+
12 +5VP
13 GND
14 STEP2-
15 STEP2+
16 DIR2-
17 DIR2+
18 +5VP
19 GND
20 STEP3-
21 STEP3+
22 DIR3-
23 DIR3+
24 +5VP

On the card (new) with the default firmware I have :
./mesaflash --device 7i76e --addr 192.168.1.121 --readhmid
IO Connections for on-card
Pin# I/O Pri. func Sec. func Chan Pin func Pin Dir
1 0 IOPort StepGen 0 Dir/Table2 (Out)
14 1 IOPort StepGen 0 Step/Table1 (Out)
2 2 IOPort StepGen 1 Dir/Table2 (Out)
15 3 IOPort StepGen 1 Step/Table1 (Out)
3 4 IOPort StepGen 2 Dir/Table2 (Out)
16 5 IOPort StepGen 2 Step/Table1 (Out)
4 6 IOPort StepGen 3 Dir/Table2 (Out)
17 7 IOPort StepGen 3 Step/Table1 (Out)
5 8 IOPort StepGen 4 Dir/Table2 (Out)
6 9 IOPort StepGen 4 Step/Table1 (Out)
7 10 IOPort SSerial 0 TXData1 (Out)
8 11 IOPort SSerial 0 RXData1 (In)
9 12 IOPort SSerial 0 TXData2 (Out)
10 13 IOPort SSerial 0 RXData2 (In)
11 14 IOPort QCount 0 Quad-IDX (In)
12 15 IOPort QCount 0 Quad-B (In)
13 16 IOPort QCount 0 Quad-A (In)


Linuxcnc claims :
hm2/hm2_7i76e.0: 51 I/O Pins used:
hm2/hm2_7i76e.0: IO Pin 000 (P1-01): StepGen #0, pin Direction (Output)
hm2/hm2_7i76e.0: IO Pin 001 (P1-14): StepGen #0, pin Step (Output)
hm2/hm2_7i76e.0: IO Pin 002 (P1-02): StepGen #1, pin Direction (Output)
hm2/hm2_7i76e.0: IO Pin 003 (P1-15): StepGen #1, pin Step (Output)
hm2/hm2_7i76e.0: IO Pin 004 (P1-03): StepGen #2, pin Direction (Output)
hm2/hm2_7i76e.0: IO Pin 005 (P1-16): StepGen #2, pin Step (Output)
hm2/hm2_7i76e.0: IO Pin 006 (P1-04): StepGen #3, pin Direction (Output)
hm2/hm2_7i76e.0: IO Pin 007 (P1-17): StepGen #3, pin Step (Output)
hm2/hm2_7i76e.0: IO Pin 008 (P1-05): StepGen #4, pin Direction (Output)
hm2/hm2_7i76e.0: IO Pin 009 (P1-06): StepGen #4, pin Step (Output)
hm2/hm2_7i76e.0: IO Pin 010 (P1-07): Smart Serial Interface #0, pin TxData0 (Output)
hm2/hm2_7i76e.0: IO Pin 011 (P1-08): Smart Serial Interface #0, pin RxData0 (Input)

And physically what's working with my stepper drivers is
1 STEP0-
2 STEP0+
3 DIR0-
4 DIR0+
5 -
6 -
7 STEP1-
8 STEP1+
9 DIR1-
10 DIR1+
11 -
12 -
13 STEP2-
14 STEP2+
15 DIR2-
16 DIR2+
17 -
18 -
...

No information source seem to have the right thing.

I miss (and I'm probably not alone) a diagram clearly saying which pin (or pair of pins) is on the card. I still need to connect my VFD on PWM and limit switches, but I fear to make a mistake and don't even know what is configured and where.
Could someone have clues ?

Thanks !

The 7I76E manual is correct (you have it miswired, it may work but its not correct)

Note: if you use single ended drives:

For common anode OPTOs (common+)
you connect the step drive common to 7I76E +5 and use the 7I76Es STEP- and DIR- pins
(the STEP+ and DIR+ pins remain unconnected)

For Common cathode OPTOs (common gnd)
you connect the step drive common to 7I76E GND and use the 7I76Es STEP+ and DIR+ pins
(the STEP- and DIR- pins remain unconnected)

Thank you ! You're absolutely right, the miswiring was a possibility as the drivers are indeed single ended common anode.

In fact I had been mislead by a wiring picture found on www.cnctablebuild.com/mesa-setup-part-1-hardware/
The drivers are now correctly wired as you decribed and work flawlessy, far faster than they previously did with mach3 and its USB controller.

For the pin numbers reported by mesaflash and linuxcnc, I was trying to understand the numbering scheme and physically locate things like "(P1-14)" but I understand they are FPGA related and we simply only need to trust the documentation and pick the needed port.