Favourite connector/cage system for multiboard systems?

Hi Phil

Haven't built instruments with card cages, but I have experience with CAMAC, VME, VXI, CPCI and ATCA.

You might want to look into PXI and PXI Express. Not the cheapest, but NI is supporting it. (replace 'but' with 'as' if you prefer)

Do you have an application in mind?

Cheers

Michael

Am 25.11.20 um 22:10 schrieb Phil Hobbs:

Is your question "Do people still use card cages in products"? Or, "What interconnect *standards* do people use for multiboard systems"?

Personally, I dislike "fingers" on PCBs as it means the board house has to know how to deposit gold AND puts tighter tolerances on that edge of the board. Instead, I prefer purchasing (gold plated, if necessary) connector pairs from a vendor who has the plating process down pat.

[It also means a bad connector can be replaced -- at a relatively low skill level -- without having to scrap the board]

My current product hard-wires boards/modules together at their edges. This to cut cost, minimize size, discourage tinkering and increase overall reliability (connectors elided).

[I rescued a DSO that's sole problem was an interconnect *board* (think of it as a rigid ribbon cable) that had become dislodged, internally.]

Can't answer the first part of the question, but the fact that board line suppliers still stock DIN41612 connectors - element 14 has 421 different parts - does suggest they do.

I first ran into them in the late 1970's, and they were a whole lot better than gold-plated fingers on printed circuit boards.

In the 1980s I used the mixed signal variants where you lost a bunch of pins and replaced them with holes for for SMB-sized coax connectors (or large diameter pins if you wanted lots of current).

There are other options, but that one does seem to be popular. IIRR VME used them.

--
Bill Sloman, Sydney

We still sell a lot of VME. VME has outlasted roughly a dozen come-and-go busses that were supposed to kill it.

We might make our own VME crate soon. They tend to be expensive.

--

John Larkin         Highland Technology, Inc   trk 

The cork popped merrily, and Lord Peter rose to his feet.   
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

IIRR VME used double Eurocards with two 96-pin DIN41612 connectors per card .

It has been extended.

My 1988 project used triple extended Eurocards to make room for enough - t hree - mixed signal DIN 41612 connector to accommodate the roughly 200 pins I needed for power and slow signals and a bunch of high speed signal distr ibuted through balanced coax links as ECL signal levels. It wasn't VME, but we got our card cages and racks off-the-shelf from Vero . There were other suppliers.

--
Bill Sloman, Sydney

Am 26.11.20 um 16:15 schrieb John Larkin:

No. VME has out-slept the competition. Does it still have the /busy-glitch? I had may share of VME fun at 80186 / 386 time, among others a 16 terminal I/O concentrator based on 80186 for Unix system V on VME 68k and Fairchild Clipper.

We moved on to Multibus 2, and if you look at PCI you can easily see who's the grandpa. The MB2 message passing coprocessor is on the bottom right:

< >

S/N 0001 took some hits in the junk box over 40 years. But hey, it has a transputer link and WD3093 SCSI! The layout was done on Orcad SDT, but, thanks goddess not by me! :-)

We used to use Vero for VME backplanes, crates, and especially the Vero Powerplane boards with power & GND planes. They were really good.

Cheers, Gerhard

We don't use /busy, so I don't know. The basic bus transactions is /ds0 and /ds1 into the target, and /dtack back. Pretty simple handshake.

Process i/o and most system hardware simulation doesn't need to be especially fast, so VME is fine for that. The big 6U eurocards have lots of room for connectors and you don't have to crawl around in the dark under a desk to get at them.

I had may share of VME fun at 80186 / 386 time, among others

What we like about VME is that people buy it in big hunks.

In a way, the crate and crate controller overhead discourages small buys from grad students and such.

--

John Larkin         Highland Technology, Inc   trk 

The cork popped merrily, and Lord Peter rose to his feet.   
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

I've used some Japanese connectors that were distributed through 3M in the US. They come in a variety of lengths, but I used the 68-pin size, mostly. Digi-Key and Mouser have them. Some of the part numbers are : P50E-068P1-SR1 and P50E-068P1-RR1-EA These connected a row of daughter cards to a motherboard. The daughter board connector is a right angle type.

These is also available a variety for crimpinng to high-density ribbon cable.

Jon

The DIN 41612 connectors come in lots of variations. Some are designed to crimp onto 64-wqy ribbon cables. Element-14 has two variations in stock in Australia.

--
Bill Sloman, Sydney