TM 11-6625-3081-23
1-20. SYSTEM FUNCTIONAL DESCRIPTION (cont)
1-20
(6) Photomultiplier Tube (PMT) Controller 1A7.
The PMT controller 1A7 provides
power to maintain the PMT at a constant temperature. The PMT is located in the
dayside test bench optical signal analyzer 2A1A1. It is a measurement device for
counting the number of photons being emitted by the CRT of the UUT.
(7) Extender Assembly 1A9.
Extender assembly 1A9 consists of two HP-16
extenders,
1A9A1 and 1A9A2.
Extender 1A9A2 is the input/output link between the
TADS/PNVS augmentation equipment and the HP-IB extender connected to (and supplied
with) the AN/USM-410 electronic equipment test station.
(a) The HP-IB extenders communicate with each other using 22-bit data
frames.
These data frames shuttle back and forth between extenders, continuously
updating each with the current state of the devices and extenders at the other end.
(b) The data frames are transmitted serially between the HP-IB extenders.
Upon arrival at the HP-IB extender, serial data is decoded and output in 16-bit
parallel fashion.
(c) Parallel data from HP-IB extender 1A9A2 is applied to the digital
computer assembly 1A1O.
The digital computer assembly transmits and receives data
from HP-IB extender 1A9A1 via the IEEE 488 bus.
Serial data shuttles back and forth
between HP-IB extender 1A9A1 and HP-IB extender 2A2A8 in the text console test
bench.
(8) Digital Computer Assembly 1A11.
The digital computer assembly 1A11 pro-
vides interface and switching control between the AN/USM-410 electronic equipment
test station and the TADS/PNVS augmentation equipment. The computer transmits and
receives 16-bit parallel data to and from the following units:
Extender assembly 1A9
Control unit assembly 1A1
488 controller power supply assembly 1A2
Multiprogrammer assembly 2A2A6
Electronics drawer assembly 2A2A7
c.
DAYSIDE TEST BENCH 2A1
(1) Optical Signal Analyzer 2A1A1.
The OSA 2A1A1 (EO bench serial numbers
00001 thru 00105) is an electro-optical test device used to test the HOD and IVD
UUTs.
The UUT is loaded into the OSA and enclosed by a light-tight door when the
test is in progress.
The OSA consists of a photomultiplier tube (PMT), shutter,
lens filter, focus lens, and a photon emitter assembly.
(a) The PMT is a measurement device used for counting the number of
photons being emitted by the CRT of the UUT.
(A photon is a unit of intensity of
light.) The PMT is enclosed in a housing which is cooled by thermoelectric elements
that pump heat to a heat exchanger, where a fan moves the heated air out of the OSA.
There are temperature and overheat sensors used for temperature control. A shutter
protects the PMT from damage due to continued exposure to light. The shutter is
programmed to open during test operations.
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