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