group meeting, 7/14/11

loc: 1140 Etcheverry, in front of Faraday cage
attendance: Charles Yeamans, Andrew Hernandez, Matt Turner, Andrew Serpa, Andrew Ludwig, Felicitas Hernandez

discussion items:
1) Steerer polarity problems (A. Hernandez): status = resolved
It appears the steerer polarity switches come up in an indeterminate state, and as such the steerer polarity may appear to not function correctly. To avoid this, either we build the pull-down circuit on the control room end of the (digital) fiber optics line or just remember to exercise the steerer polarity switch on each start-up of the control system interface.

2) steerer function problems (Turner): status = resolved
As this was ongoing during the meeting, Matt can fill in details. The steerer wiring needs to be labeled and the interconnections to their polarity switch relays’ terminal blocks documented.

3) computer purchases (F. Hernandez): status = ongoing
The CPU we wanted is not available immediately. It was resolved to request a quote for the two systems available now and order two units of the higher-performing one. One will become the dedicated Unix control/GUI and the other will be set up to run all the data-logging and other non-control functions. What is the state of the non-Kontron components order?

4) GUI (Turner): status = ongoing
The boss wants a stand-alone system that does nothing upon boot-up other than start the control interface, and performs only the control/GUI function.

5) Unix control of signal generators (Serpa/Ludwig): status = new project
Team “non-Hernandez Andrew” will attempt to interface the Measurement Computing signal generators using Unix so the GUI itself can be migrated.

6) find a programmer (A. Hernandez): status = new project
A programmer can become a DoNuTS trainee (subject to the requirements of the grant) for the purpose of writing the new Unix interface. Find a person and coordinate adding them to our program with Sherry.

Is there anything else we discussed at this meeting?

GUI (Turner)

The accelerator control system needs a user interface. Matt is designing it in Matlab and the electronics boxes need to run off of it before they are installed in the tank.

cable trays (A. Hernandez)

The parts have arrived. Erect the structure as discussed. After that, prepare for running electrical for pump stand on the the east end of the tank.

electronics boxes documentation (Serpa)

The documentation needs to be such that a person with no specific knowledge of our system could pick it, stat reading manuals, and eventually figure out what all the parts are and what they do. Pictures/drawings are very useful and don’t have to be nice or high-quality to be very valuable. Start at the top with a cartoon of all the components from the electronics boxes to the control computer and reference individual manuals. Eventually, this will all end up in a single file folder with many tabs for efficient access by everyone.

beam line assembly (A. Hernandez)

preparatory work, can be done any time:
1) Cut/fit 2 1″ layers of lead bricks for the bottom shielding. It doesn’t need to go all the way to the edge but it should be within about 1″ on all sides.
2) Design and fabricate a base plate to which the pump chamber itself mounts. The brackets that are on the exiting stands are probably a good assumption for what will be mounted to the plate to hold the chamber and turbo pump. The chamber/pump assembly weighs about 75 lbs. and will be oriented anitparallel to its lowest gravitational energy state, so the mounting will have to be substantial. Tabs have been installed on the stand for mounting this plate and/or side plates.
3) When turbo pump controllers arrive, install and test full pump setup. A vacuum in the range of 10^-6 torr should be achievable using the turbo/rough pump setup we usually use pumping against the large vacuum valve on the other side of the turbo pump.

installation, should be done only when preparatory work is complete
1) Shut down Morseified turbo controller and rough pump and wait for the turbo to spin down (may take hours).
2) When the turbo has slowed down, wheel over a tank of argon and very slowly backfill the beam tube and pump stand. Purposely hold the connection between the tank and tube fill fitting very loosely so it is not possible to pressurize the fragile beam tube.
3) Detach the pump stand at the flex coupling.
4) Move the new pump stand in to place.
5) Install the lead, mounting plate, chamber, and turbo pump.
6) Attach the chamber to the beam tube with a new 8″ copper Conflat gasket.
7) Attach a blank flange on the open end of the chamber.
8) Turn on the rough pump and open all the valves. The beam line should pump down near 10^-3 torr in fairly short order. If it doesn’t, turn off the pump and listen for huge leaks caused by improper gasket installation.
9) With the pressure below 1 torr, start the turbo pump and let it come up to speed. The vacuum pressure should be down in the 10^-8 torr range within 24 hours. If not, leak check, repair, repeat pump down.

computers (F. Hernandez)

We need to replace the guts of two Kontron 3U rackmount machines due to obsolescence and hardware failure. Since this looks just like a typical civilian project, I don’t anticipate it being to much of a time sink. The goal is to have a stand-alone machine to run nothing but the accelerator control system and a separate general-use machine for all the ancillary experiment-specific DAQ and data-processing applications.

components needed are:
1) motherboard
2) CPU
3) graphics card (preferably one card with 2 DVI-D connectors)
4) hard drive (2 x 1TB each machine, so 4 total)
5) RAM (4 GB per machine)

I suggest direct communication with Kontron for items 1 and 2, and a standard consumer electronics vendor like Newegg or similar for 3-5. Other miscellany may be suggested. I’ll start by suggesting an Ergotron MD102 or similar, plus a Morsified Samsung 203b, should make an adequate accelerator control display.

back in business

The source is running with all DoNuTS electronics.

accelerator control system (1)

Now that we’re moving on the electronic rebuilding phase. Here’s a short description of how the accelerator control system will actually work.

terminal elec–FO-|…………………………………………|—-USB input
……………………………|-FO–analog control panel–|
source elec—FO-|…………………………………………|—-USB output

Within both the source and terminal electronics boxes, analog voltage control (input) and analog voltage monitoring (output) interface with the fiber optics (FO) boxes and are converted to digital FO signals. The signals are converted back to analog at the control panel. To interface with the control panel, we will be getting two USB devices: one 8-channel input (plus 2 output channels) and one 16 channel output. Both units come with enough binary digital I/O channels to choke a horse. The fiber optics portion of the system should be transparent to us, provided it functions as ordered.

This system has some useful features.

• It incorporates full feedback for every controlled parameter. As obvious as this seems to me, there are a lot of fancy-pants scientific equipment that misses this, and thus can’t make basic determinations as to whether or not their equipment is functional.
  “What is the voltage output to the y-steerer?”
  “Uh, I turned the control knob up to 11, so I guess 11.”
  “Is the beam being steered?”
  “Uh, doesn’t look like it.”
  “So is something wrong?”
  “Uh, probably.”
• Since we have feedback, we have the option of closing the feedback loops with controllers in the future. Process control can be tricky, so starting out your system with closed feedback control on everything leads to a lot of fighting control systems and less actual running the accelerator, so we have the option to do it later but we don’t have to do it now.
• The control system has a natural analog breakout point at the control panel. If something isn’t responding correctly from the computer, you can stick a voltmeter in the control panel and see if you’ve got the correct signal going through, rather than trying to figure out if the baud rate on your RS232 device interface is set correctly or is your port forwarding settings mesh with the new TCP/IP management software the department installed.

vacuum pump controller (2)

So apparently buying custom PCBs is taboo, so we’ll be rolling our own. The upside is no one outside the lab need look at our precious proprietary developmental super-secret awesomeness. The downside, is there is a lot of precision drilling in everyone’s future. Stay tuned for further developments.

vacuum pump controller (1)

It looks like a number of vendors offer short-run PCB prototype production. As much as I love playing with toxic chemicals and then properly disposing of the waste, contracting out the PCBs for our vacuum pump driver/controller units may turn out to be straight-up cost-effective, as well as a time-saver.

http://www.custompcb.com/

http://www.futurlec.com/PCBService.shtml

Others may exist as well.

1. Finalize the layout, including the bearing RTD readout. That can be as simple as a light that turns on when the resistance of the RTD circuit goes above the 35 degC value.
2. Find some protoytpe PCB-fab companies and get quotes for 8-12 units. They probably want the original layout file.
3. Order the boards.
4. Develop parts list from the prototype and notes on the circuit diagram.
5. Order the components from any of our favorite electronics components vendors. Try to get it all in one order.
6. When everything shows up in the lab, stuff a board and solder it. See if works in the prototype chassis.
7. Figure out how to use the old broken controller transformers and cases to actually assemble a functioning 1/2-rack mount unit, probably requiring a new front faceplate.
8. When one fully-built controller works, repeat to build 6 total functioning units.

#stuff2do