Choising an I/O module

Question

Hello,
I was wondering how can we choose an I/O module? my module needs to cover an input which varies from 0 to 25 V and with this module, we can choose a square signal, continue or triangle. Which module matches my characteristics? i've read the datasheet and i came across NI 9221. Can i use this module?
What do TTL,Sink/source mean? when the datasheet indicates that the signal level is 60VDC, does it mean it cover from 0 to 60?
Thank you.
Dhirah

Answer 1

Hi!
   Your task seems not really clear
   If you need 24 Volt input/ output, NI 9422 and NI 9474 are good.
   NI 9422:
   Number of channels..........................8
   Input type..........................................Sinking/sourcing
   Digital logic levels
   OFF state
   Input voltage ........................≤ 5 V
   Input current.........................≤ 0.17 mA
   ON state
   Input voltage ........................ 11 to 60 V
   Input current.........................≥ 1.2 mA
   Ni 9422 is a DIGITAL input module.  I cannot find max sampling frequency achievable, I only read 250 us max delay in input.
    NI 9474 is a digital output module, with 8 channels, sourcing. i.e. when you turn on the single channel, you provide + 24 Volt to the load.  You have to carefully read the manual to check if it fulfills your load's specifications!
   If you need Relay out,NI 9481 has 4 relays (4 output channels), SPST.  I've found no more relay modules, this is a problem if you need more sofisticated relays  (SPDT, etc....), you'll have to turn to another system, or you integrate some other electronics.
graziano
PS.: this was the my last answer for free to have better details you can phone NI, they're really kind both in commercial and support!
Message Edited by Graziano on 04-17-2008 09:15 AM