I've made up some panels for a new 1U chassis to house the acromag controls of the two TTFSS boxes.  It makes sense to mount them in a separate 1U chassis. The D25 connectors into the FSS interface boxes have enough binary engage and analog channels to take up all the inputs and outputs of an XT1221 and an XT1541 card. The whole experiment needs to be taken down while someone modifies the main crate, this way we modularize it a bit.

This will neatly package all the computer controls together with the two rack interface boxes and remove some of the clutter from the front panel.  The package will take standard 24 V plug, along with a panel mounted Ethernet and a pair of  Sub D 25s. I've also included some standard 9.7 mm D holes (NOT THE 0.5", PCB STYLE) for general purpose slow monitor channels for the autolocker. These are optionally on the back or front.  

The panels are the only part we need. Everything else is in stock.

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Aidan had a good way of mounting the Acromags in the standard 1U boxes.  He put a DIN rail vertically, bolted into the sides. From there we can just manually wire everything up.  

We will also need a 5 V source to excite the binary channels. It doesn't need to be clean, its driving a binary comparator.  An LM7805 would maybe work off the 24 V line. There is a 24 mA of current which means 123 mW of power dissipation.  These TSR-1 DC/DC converters look cool, but not sure I want to introduce something with a switching frequency of 500 kHz anywhere near our electronics.