50-pin Digital Connector info

[K1200LT_rider]

I had a hard time finding info about getting a cable or plug that would fit the very high density, 50-pin digital connector on the front of our PXI-5411 card.  Some other cards with the same connector are (so searches will hit on this message):

PCI-5401

PXI-5431

PCI-5411

PCI-5431

The similar 68-pin VHDCI connectors used on other NI cards is much easier to find cables or plugs for outside of NI since it is a SCSI standard.  At first I was searching on VHDCI looking for anything with 50 pins and had no luck.  But, after almost a day of searching and calling around (including NI sales), I found a diagram of a connector somewhere online that showed the terms "VHDCI" as well as "0.8mm CHAMP."  The latter was the magic term to search for.  Searching on that showed that Tyco Electronics (AMP) makes the separate connectors as well as double-ended cables.  After I found this info on my 2nd day of searching, NI called me back and said that they actually have one cable that will plug into that connector.  It is NOT listed anywhere on their site or even in the old NI catalog that listed my PXI-5411 card, so searching for it on ni.com will turn up nothing.  Here is the info for the 2 lengths they have:

Description: SHC50-68 cable, 1 meter

Part Number: 184748-01

Price: $129

Description: SHC50-68 cable, 2 meters

Part Number: 184748-02

Price: $139

I'm not too happy about the lack of info in NI's documentation about this connector.  If anyone from NI reads this, please make these suggestions to anyone concerned inside the company:

1. Mention (in the card/equipment documentation and online) the industry-standard name for all connectors used on all hardware.

2. Put ALL present and past items somewhere online or in a database so that a search can at least turn up a clue as to whether or not something is still available.

If either of these items would have been there I would have wasted much less time finding and ordering the cable from NI.  The lack of information availability from NI is sometimes very frustrating.

- Brad

[Drew Creel · Accepted solution]

Brad,

I apologize that you had a hard time finding information on this connector;  you are right, VHDCI is not a very common name for this connector.  Apparently there are many different names for it, including VHDCI, CHAMP, micro-ribbon, SCSI 1 (it is a very old SCSI standard), "narrow SCSI", D-type, etc.  I will file requests to refer to some of these more common names in our documentation and on our website.

Regarding the SHC50-68 cables that we sell, if I'm not mistaken those actually have a 50-pin connector on one side and a 68-pin connector on the other.  Are you looking for a 50-pin to 50-pin cable, or something to convert to 68-pins?  That may be the reason the cable did not come up in your initial search.  Another reason is that the 5411 has been obsoleted; we no longer sell them (but we still support them), and that cable used to be located on the 5411 product page (which no longer exists).  I will see if we can make the SHC50-68 cable easier to find on our website.

Thank you for bringing this to my attention.

________________________________
Drew Creel
NI Software Group Manager
Signal Generators Group

[K1200LT_rider]

Drew,

Thanks for the reply and effort to help out others with these older cards.  The 50 to 68 pin NI cable will end up perfect since it will plug into a SCB-68 interface box.  If that wasn't available we would have built our own cable from the parts available from Tyco electronics.  Just as a side note: the premade 50-pin to 50-pin AMP cables that Tyco has are not really usable with the NI sig gen cards.  We were thinking about buying one of the longer ones, cutting it in half, then attaching another connector or SCB-68 box, but the pins are wired up in groups of 3: twisted pairs along with a 3rd pin connected to a separate shield for each pair.  I suppose you could still make it work in a pinch by picking the appropriate signals to use so that each one used is in a different twisted pair within the cable.  But this would probably work if you only need a few digital signals, etc.  So, I have only found 2 practical solutions for connecting to the 50-pin digital connecter to the outside world:

1. The NI 50 to 68-pin cable

2. The individual AMP connector plugs and 0.8 mm ribbon cable (or individual wires) to make your own.

The problem with #2 is that you have to press to push the wires into these IDC (insulation displacement) type connectors.  There are no solder types available for making cables.  I found the ribbon cable made by Madison Cable.  Ribbon cable with 0.8 mm conductor spacing is apparently very uncommon.  Neither Digi-Key nor Newark list any with that conductor spacing at all.  No one stocks it.  It will take some lead-time to get it.  We ordered some along with some connectors so we have an alternative way to connect to the digital connector if the need ever arises.

One other thing: the term VHDCI refers only to the 68-pin SCSI-3 type connector (http://en.wikipedia.org/wiki/Vhdci).  That's why I couldn't find anything having to do with 50 pins when searching on that term, even though the connectors are basically the same format.

Thanks again,

Brad