EG&G ORTEC 476 Manuel d'instruction - Page 6
Parcourez en ligne ou téléchargez le pdf Manuel d'instruction pour {nom_de_la_catégorie} EG&G ORTEC 476. EG&G ORTEC 476 14 pages. Multiplexer/routar
Imprimer la pageEG&G ORTEC MODEL 476 MULTIPLEXER/ROUTER
1.
DESCRIPTION
1.1.
PURPOSE
The EG&G ORTEC 476 Multiplexer/Router is a modular
nuclear instrument that will interface a quantity of detec
tor-preamplifier-amplifier circuits into a single data
accumulation system and provide for simultaneous stor
age of their separate spectra. Each of the detector-pre
amplifier-amplifier circuits is connected to the analyzer
through one of the multiple channels in the 476. The 476
then provides the multiplexed analog signals for all chan
nels, together with logic levels, to indicate the unique
channel through which each analog signal was processed.
If the data acquisition system is set to respond to the logic
signals as intended, its total memory is subdivided so that
a unique spectrum can then be accumulated for the sig
nals from each of the detector-preamplifier-amplifier
channels.
There are three basic versions of the EG&G ORTEC 476
Multiplexer/Router. The 476-04 includes four input chan
nels: the 476-08 includes eight channels: and the 476-16
includes 16 channels. This manual will discuss, primarily,
the 476-16 version. The principles of operation and the
logic are similar for each of the other two versions.
1.2. PHYSICAL DESCRIPTION
The 476 is built in a double-width NIM module that must
be installed in a standard bin and power supply for opera
tion. All of the input signal connections are included on
the front panel, together with individual fine gain controls
for each channel and other operator controls. The multi
plexed analog output and the binary-coded, logic channel
identification output are on the rear panel.
A common threshold control is included on the front
panel. This permits the operator to adjust an input ampli
tude threshold for all channels: it is normally set just
above system noise. A toggle switch permits the operator
to select any single channel, together with the rotary
selector switch at the upper right, so that its gain can be
adjusted conveniently. The toggle switch is normally set
at the Multiplex position, and the rotary switch is ineffec
tive since all channels are active.
1.3.
RELATED EQUIPMENT
The design of the 476 Multiplexer/Router is compatible
with the EG&G ORTEC 7000 Series Data Acquisition and
Analysis Systems (DAAS), and can be easily customized
for operation with other multichannel analyzer systems
such as the EG&G ORTEC 6240B. Internal jumper selec
tions permit the subgroup selections to affect any two,
three, or four adjacent address bits from 2® through 2".
This allows subgroup routing to be used for a wide variety
of total memory capacities, which are available in these
analyzers. Mode selection signals and timing logic signals
are also included in the interconnections.
To permit very large systems to be developed, there is a
provision for jumper selection to activate a particular 476
where there can be as many as four of these units in the
system. This provision could conceivably permit a system
to be organized with as many as 48 separate detector-
preamplifier-amplifier input channels and with unique
storage of the spectrum from each channel.
2.
SPECIFICATIONS
2.1.
PERFORMANCE
MULTIPLEXING CAPACITY
One to 16 linear (analog)
channels in the 476-16:8 channels in the 476-8:4 channels
in the 476-4.
EXPANSION CAPABILITY
Provisions to expand to
three multiplexing modules.
ANALYZER MODE IDENTIFICATION
Jumper selec
tions to identify any one of three possible analyzer modes.
TIME CONSTANT
Each channel includes switching to
match the time constant of the amplifier from which the
signals are furnished: 1-, 2-, 3-, or 6-^8 shaping can be
matched.
ISOLATION
Typically 65 dB from any off-channel.
OPERATING TEMPERATURE 0 to 50° 0 (273 - 323K).
DC LEVEL SHIFT
<0.1 mV/°G.
INTEGRAL NONLINEARITY
<0.1%.
NOMINAL GAIN = unity.
GAIN STABILITY
50 ppm/°G.
GATING
Internal logic gates an analog signal through
the 476 for the identified channel only: automatically
locks out response in all other channels. Also accepts
external ADG Busy signal to inhibit switching of analog
signals until the ADG has finished processing the signal.