My Mesa 5i25 board has a problem with GPIO.

Hi,

Today when i had checked my mesa 5i25, i saw a weird thing. I just check gpio and see some pins are not pull-up.


here is my hal command:
loadrt hostmot2
loadrt hm2_pci
loadrt threads name2=test2 period2=1000000
addf hm2_5i25.0.write test2
addf hm2_5i25.0.read test2
loadusr halshow
start

And my bitfile and vhd file:


these pins were used to read encoders.
now i still can read signal by these pins.

If you read this with nothing connected to the 5I25, its likely means that either the FPGA or the bus switch
has been damaged by excessive input voltages, that is, voltages outside of the range -0.5V to +7V.
This is _very_ easy to do of you wire noisy devices directly to FPGA pins.

i didnt notice that, i thought everything are fine , should i leave these pins or still use it to read encoders?

Are you connecting the pins of external encoder directly to the 5I25 pins?

The problem with encoder pins is that the encoders are connected to servo motors and may carry several volts of high energy noise coupled from the servo drives high voltage PWM, This not an issue when you use a daughtercard/breakout board intended for encoder signals since they are designed to deal with this, but if you wire encoder signals directly to FPGA inputs you are likely to cause damage, At the minimum if you want to do this is to add about 100 Ohm series resistors, these will at least protect the input clamp diodes from excessive current.

Is 7i75 board enough safe to solve this ? I'm not sure 12V enough safe for an AC servo because i dont have much experience. I also look into another daughtercards but they have some functions that i dont need

I have a similar problem, and the input pins of the Mesa 7i95 are randomly active. I have supplied a voltage of 24 volts to these pins mistakenly. I have to use some input output functionality in real-time. what is another way to use some input output?

Which inputs pins? 

The isolated inputs TB6 + TB5 pins 1..12 will accept from 5 to 36V

Thank you for the quick reply. 

I am trying to use input pin 0 on the TB6 tab of the Mesa 7i95 board. I am supplying 5 volts on and off, but the status of the input pin (hm2_7i95.0.gpio.000.in) is not changing in the Halshow monitor window, but the LED of the mesa board of the 0 input pin is getting on and off.
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I want to add an emergency stop and feed override button.

I have asked the same question ("Adding external switch for emergency stop and feed override") in my thread posted one day before, requesting you to look at that also if possible.

How is the input wired?

The 7I95/7I95T input pairs have an input common
so if you are supplying +5V to the input, the input common
must connect to 5V common (negative)

Note the you have to have 5V to reliably activate the input
4V is marginal (the input threshold is about 3.9V)

Make sure you are using the "WATCH" tab in halshow
not "SHOW"

Also note that  the 7I95/7I95T isolated inputs are not hal GPIO
pins but rather hal Inmux pins (0..23). 
 

Thanks for the "inmux" hint, it's so true that the 7i95 board has inmux-type input and output pins. Now I have connected the right input pin, and my external emergency stop button is working fine. I have added the following hal command line in my .hal file...

net estop-out iocontrol.0.user-enable-in
net external-estop-in hm2_7i95.0.inmux.00.input-00 => iocontrol.0.emc-enable-in

Let me know if it can be further simplified.

Kindly do me another favor by giving the piece of hal command line to do the x-axis feed override control using an external analog DC power supply from 0 to 10 volts