Question about SCB-68A

[orangeheart]

I am connecting a photon counting head through SCB-68A with 6612. My questions are:

1. The output of the photon counting head is TTL, which digital DIO termials should I connect to on the SCB-68A, P or PFI? What is the difference?

2. The photon counting head output need a 50 ohm impedance. What is the standard way of adding this impedance? Should I use a 50 ohm BNC terminator before SCB-68A?

Hope someone could help me here. Many Thanks!

Alex

[Cortega]

Hi Alex,

Regarding your questions:

1. You can use both PX.X terminals and PFI X terminals as a Digital Input, the difference is that PX.X ports are dedicated only for Digital I/O signals, PFI X ports are known as Programmable Function Interfaces, the advantage of them is that depending of your card, you will have the option to program them as terminals for clock synchronization, triggers or counter I/O.

Check the next document for more information about the pinout terminology of the terminal blocks:

Pinout Terminology and Definitions for NI DAQ Devices

http://www.ni.com/product-documentation/54464/en/

2. This will depend of the type of impedance the sensor will need. It is pull-up, pull-down, current driver? Normally, the user manual of the sensor explains how this will work.

Hope this information will be helpful for you.