"Core shield" grounding of SHC68-68-EPM cable with PXIe-4309 ADC

[JeBolduc]

Hi,

I am using the PXIe-4309 ADC to perform signal measurements on a device (some signal source) and I was trying to figure out how I should ground the core shield of the SHC68-68-EPM cable I am using (through the TB-4309 (MT) terminal block). The fact that National Instruments documentation seems to contradict itself on that matter caught my attention.

Looking at the dimensional drawings (file:///C:/Users/jebolduc/Downloads/cu_shc68-68-epm%20(4).pdf) , I understand that the "core shield" is the inner shield and is connected to pin 54 and that the outermost shield is connected to both connector shells.

Reading some NI documentation, I can understand that they recommend putting both connector shells to chassis ground and grounding the "core shield" only to one side, and specifically to the "signal source" (my device) side. However, looking at the TB-4309 (MT) terminal block connector pinout, we can see that pin 54 is a GND which is contradicting their recommendations...

Source: PXIe-4309 user guide

Source: https://www.ni.com/en-ca/support/documentation/supplemental/06/field-wiring-and-noise-considerations...

Source: GETTING STARTED GUIDE AND TERMINAL BLOCK SPECIFICATIONS PXIe-4309 and TB-4309 (ST)/TB-4309 (MT)

In my case, that is not critical and won't change anything but I was just trying to make sense of it.

Thanks  in advance,