input impedance with SCXI-1313

[NAUSHICA]

I am using SCXI-1125 with SCXI-1313 as the terminal module.
What is the input impedance when 1313 is set to attenuation mode (0.01 gain) and no att. mode (gain = 1)

Rg

naushica

[Tom.]

Hi,

The input resistance will be related to the SCXI-1125 input module and not the SCXI-1313 attenuating module.
The specifications for the 1125 can be found here - http://www.ni.com/pdf/manuals/322425a.pdf, with the information you are looking for being on page 47.

The impedance is listed as :

Powered on ..................................... 1 Gohms
Powered off..................................... 4.5 Mohms
With SCXI-1327 ............................. 1 Mohms

Hope this answers your question 🙂

Tom.

NIUK

[Logan_K]

I appologize for contradicting the previous answer, but when the SCXI-1313 is using the 100:1 attenuator, it uses a voltage divider which will result in an input impedence of 1Mohm. When the attenuation is 1:1, the input impedence will equal the impedence of the SCXI-1125 (~1Gohm).

The SCXI-1313 installation guide describes this attenuator resistance:
http://www.ni.com/pdf/manuals/322853a.pdf

-Logan K.