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Entry  Fri Nov 4 18:31:05 2016, Lydia, Update, CDS, c1auxex channels/pins for Acromag 
    Reply  Sat Nov 5 15:45:44 2016, rana, Update, CDS, c1auxex channels/pins for Acromag 
       Reply  Mon Nov 7 19:49:44 2016, Johannes, Update, CDS, acromag chassis hooked up to PSL acromag_chassis_location.jpgacromag_chassis_top_view.jpg
          Reply  Tue Nov 8 17:51:09 2016, Lydia, Update, CDS, acromag chassis hooked up to PSL 
             Reply  Mon Nov 21 19:54:13 2016, Johannes, Update, CDS, acromag chassis hooked up to PSL acromag_chassis.jpg
                Reply  Wed Nov 30 11:56:56 2016, Lydia, Update, CDS, Wiring for Acromag auxex replacement auxex_acromag.pdf
                   Reply  Wed Nov 30 14:54:01 2016, Johannes, Update, CDS, Slow machine replacement 
                      Reply  Wed Dec 14 19:16:57 2016, Lydia, Update, CDS, Acromag Binary I/O testing 
                         Reply  Tue Jan 31 22:15:02 2017, Johannes, Update, CDS, vme crate backplane adapter boards vme_backplane_conn_sketch.jpg
                            Reply  Tue Feb 7 19:14:59 2017, Johannes, Update, CDS, vme crate backplane adapter board layout vme_backplane.pdf
                               Reply  Wed Feb 15 00:26:44 2017, Johannes, Update, DAQ, panels and pcbs acromag_chassis_panel.pdfvme_backplane_panel.pdfrfAmp.pdf
                                  Reply  Wed Feb 15 09:06:13 2017, ericq, Update, DAQ, panels and pcbs 
                                     Reply  Wed Feb 15 22:21:12 2017, Lydia, Update, DAQ, panels and pcbs 
Message ID: 12781     Entry time: Tue Jan 31 22:15:02 2017     In reply to: 12677     Reply to this: 12810
Author: Johannes 
Type: Update 
Category: CDS 
Subject: vme crate backplane adapter boards 

I made a crude sketch for how Lydia and I envision the connector situation on the back of the vme crates to be solved. Essentially the side panels of each crate extend about 2" (52 mm) beyond the edge of the DIN connectors. This is plenty of space for a simple PCB board. The connector of choice is D-Sub. We can split the 64 used pins into 2x 37 D-Sub OR (2x25 pin + 1x15pin). The former has fewer cables, but a few excess unused leads. A quick google search showed me that it is much cheaper to get twisted pair cables for 15 and 25 pin D-Subs. From what I remember, the used pins on the DIN connectors are concentrated on the low numbers end and the high numbers end, so might not need the 'middle' connector in many cases if we decide to break it up into three. I have to check this with Lydia though.

The D-Sub connectors would be panel mounted, for which we need a narrow panel piece with dsub cutouts. We can run horizontal struts across the vme crate from side panel to side panel. This way the force upon cable (dis)connection is mostly on the panel which is attached to the struts which are attached to the crate. This will also prevent gravitational sag or cable strain from pulling on the DIN connection, and we can use twisted pair cables with backshell, screws, and strain reliefs.

I was lookng into getting started with the PCB when Altium complained that the license is expired and to renew it. This is a relatively simple board layout so some free software out there is probably enough.

Attachment 1: vme_backplane_conn_sketch.jpg  390 kB  | Hide | Hide all
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