7i76e + plasma wiring questions

I'm upgrading my plasma table, switching driver boards from the typical $20 Chinese Mach3 style BOB I had running on LinuxCNC2.7 to a 7i76e driver board running on LinuxCNC2.8.

So far I have a couple of questions.

First, on TB4 Spindle which pins should I be using to wire my Powermax 45XP arc start (green & black leads 3 & 4) into? I'm guessing TB4 pin #'s 3 & 1?

Second, I have my 3 stepper motor controllers wired into the 7i76e TB2 pins. In pncconfig I entered my motor values from old config file and when I go into motor tuning the 7i76e board's green led's all light up at once. However, after enabling the motors I can't get any of the X Y or Z axes to move. The TB2 pins and the controllers are all powered but the motors themselves are not powering up at all for some reason...any ideas would be greatly appreciated!


plaz@plaz-OptiPlex-990:~$ mesaflash --device 7i76e --addr 10.10.10.10 --readhmidConfiguration Name: HOSTMOT2

General configuration information:

BoardName : MESA7I76
FPGA Size: 16 KGates
FPGA Pins: 256
Number of IO Ports: 3
Width of one I/O port: 17
Clock Low frequency: 100.0000 MHz
Clock High frequency: 200.0000 MHz
IDROM Type: 3
Instance Stride 0: 4
Instance Stride 1: 64
Register Stride 0: 256
Register Stride 1: 256

Modules in configuration:

Module: DPLL
There are 1 of DPLL in configuration
Version: 0
Registers: 7
BaseAddress: 7000
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

Module: WatchDog
There are 1 of WatchDog in configuration
Version: 0
Registers: 3
BaseAddress: 0C00
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

Module: IOPort
There are 3 of IOPort in configuration
Version: 0
Registers: 5
BaseAddress: 1000
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

Module: StepGen
There are 5 of StepGen in configuration
Version: 2
Registers: 10
BaseAddress: 2000
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

Module: QCount
There are 1 of QCount in configuration
Version: 2
Registers: 5
BaseAddress: 3000
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

Module: SSerial
There are 1 of SSerial in configuration
Version: 0
Registers: 6
BaseAddress: 5B00
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 64 bytes

Module: LED
There are 1 of LED in configuration
Version: 0
Registers: 1
BaseAddress: 0200
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

Configuration pin-out:

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)

IO Connections for P1
Pin# I/O Pri. func Sec. func Chan Pin func Pin Dir

1 17 IOPort None
14 18 IOPort None
2 19 IOPort None
15 20 IOPort None
3 21 IOPort None
16 22 IOPort None
4 23 IOPort None
17 24 IOPort None
5 25 IOPort None
6 26 IOPort None
7 27 IOPort None
8 28 IOPort None
9 29 IOPort None
10 30 IOPort None
11 31 IOPort None
12 32 IOPort None
13 33 IOPort None

IO Connections for P2
Pin# I/O Pri. func Sec. func Chan Pin func Pin Dir

1 34 IOPort None
14 35 IOPort None
2 36 IOPort None
15 37 IOPort None
3 38 IOPort None
16 39 IOPort None
4 40 IOPort None
17 41 IOPort None
5 42 IOPort None
6 43 IOPort None
7 44 IOPort None
8 45 IOPort None
9 46 IOPort None
10 47 IOPort None
11 48 IOPort None
12 49 IOPort None
13 50 IOPort None

plaz@plaz-OptiPlex-990:~$

You should wire arc start to TB4 pins 5 and 6

the + lead goes to TB4 pin 6
the - lead goes to TB4 pin 5
(if you get the polarity backwards it will be stuck on)

The most common reason for lack of stepper movement with Mesa cards is having
the step length set too short, so its best to start with something like these timings:
steplen 5000
stepspace 5000
dir setup 20000
dir hold 20000

I checked and the default step timings are at 5k already, I was able to increase the direction timings from 5,000 to 10,000 then the pnc wizard greys out anything above 10k.

No luck yet with powering the motors once I click "enable" under motor tuning.

I'm using the M5045 ST-M5045 CNC 4.5A Micro-stepping Stepper Motor Drivers. Nema 23 steppers.

I double checked the wiring between the motor drivers and the board, everything seems proper and I am getting voltage readings in the 5v range everywhere at each end of wires running between the TB2 & the stepper drivers.

I'm trying to think what else I could be missing but am drawing a blank at the moment.

Do the drives have an enable?
On step drives this is usually a _disable_ input

If you don't have locked motor shafts. its probably an enable issue

Yes each of these stepper motor drivers do have Enable +/- pins, each are properly wired to the 7i76e and my voltmeter shows each are receiving their 5v from their respective pins on TB2.

Hence the reason I can't see any reason why the motors are not locking and giving movement under the motor tuner.

Is "a _disable_ input" something I need to add into code somewhere? My linux knowledge is very basic, I've only built 1 table using it and this is my first time upgrading to a higher quality board so please forgive me for any stupid questions!

Thank you Tommy...I disconnected the EN wires and we have plasma table liftoff!

As I was unwiring my old setup earlier today I wondered why the EN's were still never hooked up on the drivers...so many things in life I've had to learn twice...thanks for the reminder =)

So I have table motion now, my "bare bones" LinuxCNC config loads and the motors run as expected.

However when I try to go back and add the THCAD 10 encoder in the PNCConfig tabs, if I then go into motor tuning my Z motor acts strange...the Z moves in the intended direction but not steadily or at the intended rate and also will keep moving for several seconds after I let off the motion up/down arrows.

Then when I save this config with the encoder as Z encoder and try to load LinuxCNC it crashes and gives me this crash report:





Finally, I put try to hook the "arc on" leads to the spindle terminals TB4 5&6 the torch immediately fires when I go to hook up my second wire, for some reason the signal is feeding directly through these two terminals?

1. You do not use the THCAD as an encoder nor should you setup any Z axis encoder in pncconf for a step/dir system

2. If you get the TB4 pins 5/6 polarity reversed, they will appear stuck-on