7i95T spindle control via Modbus RS485 and SPINX1A

Hi guys, 
As my lathe drives are now with step dir, I decided to replace my 7i97 with a 7i95T. The problem is that the new board does not have analog outputs and I will have to command two vfd's.

• spindle vfd - I wanna command this over modbus RS485, using one of the 7i95T serial ports (now I was using AOUT+-, ENA+, ENA-, do I still need to send the enable signal to the VFD if I use modbus)
• toolpost grinder vfd - using the SPINX1A acting like a potentiometer. Here I'm hoping to use one of the step dir outputs as an input for this board

I will use both serial ports, on the other port I have a 48 inputs card. 
I understood that I need to write a custom bit file in order to be able to use modbus via mesa serial ports
How can I get the custom firmware for this?

Thanks, 
Vasi Mihalca

There's existing firmware with a UART on one serial port:
7i95t_1pktv2d.bin, but it sounds like you need 1 PWMgen also
so that would require custom firmware. I can make this firmware
sometime this week when I get a chance

Note that the mesa-modbus support is basically experimental
at this point and does have some known bugs.

Can I use that PWM Gen from one of the 6 step dir outputs or is it mandatory to use the expansion port. Can I have two SPINX1A in case mesa modbus is not stable enough for me?

Yes, the PWMgen outputs can be either step/dir TB pins or the expansion port

When you make the firmware, can you make it so that the last two step dir ports have pwm support. I case I don’t like how modbus works, I can use two SPINX boards for my vfd’s

Regarding modbus, is this UART stuff noise imune? Is this approach with modbus controllable with mb2hal?
I have zero experience with modbus so far, but I would want to be able to read some status like torque and power consumption.

 

7I95T configuration with 1 sserial, 1 PktUART, and 2 PWMgens
on step/dir channels 4/5. I have left the PWM dir pins as GPIO
in case you want to use them for enable or some other function
instead of direction.

Thanks for the firmware, I just wrote it to the board.
I am a bit confused about the two PWMgens.
With this firmware, what are the pin functions for channels 4/5.
On my 7i97, I was using pwmgens to create that 0-10v analog signal.
Does it means that these pins now are providing an analog signal?
Do I still need that SPINX board if I wanna control an analog spindle vfd?

Regarding modbus, will I be using that mb2hal with the firmware that's on the board?

The pin functions are listed in the .pin file included
in 7i95t_2pwm_1pkt.zip

You still need the SPINX cards if your VFD needs an
analog voltage because the 7I95 Pins jus provide PWM
signals (some VFDs will take PWM though)

I was looking into that file and wondering why the pins TB4: 4,5 and TB5: 10,11 are not outputing a DIR

TB3-2,3 0 IOPort StepGen 0 Step/Table1 (Out)
TB3-4,5 1 IOPort StepGen 0 Dir/Table2 (Out)
TB3-8,9 2 IOPort StepGen 1 Step/Table1 (Out)
TB3-10,11 3 IOPort StepGen 1 Dir/Table2 (Out)
TB3-14,15 4 IOPort StepGen 2 Step/Table1 (Out)
TB3-16,17 5 IOPort StepGen 2 Dir/Table2 (Out)
TB3-20,21 6 IOPort StepGen 3 Step/Table1 (Out)
TB3-22,23 7 IOPort StepGen 3 Dir/Table2 (Out)
TB4-2,3 8 IOPort PWM 0 PWM (Out)
TB4-4,5 9 IOPort None
TB4-8,9 10 IOPort PWM 1 PWM (Out)
TB4-10,11 11 IOPort None


From what I can see, the SPINX1A board takes as input PWM, ENA, DIR.
Will I receive a direction on these pins? TB4: 4,5 and TB5: 10,11
From where should I provide the sigbal for the ENA pin of the SPINX board?

The direction pins have been left as GPIO since this is usually
more flexible, that is, you can always make GPIO pins direction output
pins in hal but if they were PWM direction pins that's all the can be.
So for example if you did not need direction on one PWM channel
a PWM direction pin would be wasted.

The additional enables could come from 7I95T SSR outputs or P1 pins