LAT Electronics, Data
Acquisition & Instrument Flight SoftwareACD-Test-Stand #5
Noteworthy for this test-stand
can handle 12 FREE card connections on the primary GASU and 12 on the redundant GASU for a total of 6 complete BEA assemblies
supply voltage and frequency to FREE can be varied with this version of GASU to explore FREE margins
only tested at room-temperature
boards are coated/staked so should be usable for TV and vibration
CAUTION
the CALSTROBE delay and/or the TACK delay in the trigger sequencing register must not be set to 02 (hex). If set to 02(hex) the AEM will continually assert the NSCMND lines to all 12 FREE boards.
use LAT-TD-0327-03, see below, since revision 02 had JL153 pin-out error
The ACD-power switching circuit is now incorporated on the main PCB in the GASU. Metal packages are used for the switching transistors on the GASU board.
The GASU-Power Supply supplying the input power to the 12 FREE switching circuits is set at 3.7V. The final value for flight will be chosen after more tests have been completed . The output voltage range can be shifted via the V-adjust function to yield the range desired.
Here are copies of the documents for reference. Retrieve directly from LAT-DOCs for released versions.
LAT-TD-03664 GASU-Based Teststands: Describes GASU-based test-stands; has pictures of GASU panel connectors, JL153 pin assignments, etc.
LAT-TD-04267 Test for EGSE ACD G3 Test Stand with GASU Instrumented to Simultaneous Test up to 12 FREE Cards (including Safe-to-Mate): Test procedure to test this G3 test-stand, includes set-up diagram/instructions for test-stand, use in conjunction with LAT-TD-03664
LAT-TD-04269 Limitations and Deviations for G3 #5 (as-built)
NCR's (none to date)
Supporting Documents:
GASU DAQ Board schematic with new power-section
LAT-TD-00639 ACD Electronics Module
LAT-TD-01545 Global Trigger Electronics Module
LAT-TD-01547 Command/Response Unit
LAT-TD-01546 Event-Builder Module