920E EtherNIM 16 Input Multichannel Buffer

Specifications

PERFORMANCE

ADC  Successive-approximation type with sliding scale linearization.

MAXIMUM RESOLUTION  4096 channels, software selectable independently for each segment as 64, 128, 256, 512, 1024, 2048, and 4096.

DIGITAL OFFSET  Independent for each segment in increments of 1 channel from 0 to 4096.

CONVERSION TIME PER EVENT  15 µs (fixed).

INTEGRAL NONLINEARITY  ≤±0.025% over top 97% of dynamic range.

DIFFERENTIAL NONLINEARITY  ≤±1% over top 97% of dynamic range.

GAIN INSTABILITY  <50 ppm/°C.

DEAD TIME CORRECTION  Extended Live-Time correction according to Gedcke-hale method.3

DATA MEMORY  16k channels of nonvolatile memory; 2³¹–1 counts per channel (over 2 billion).

PRESETS

Real Time/Live Time  Multiples of 20 ms.

Region of Interest  Peak count/integral count.

Data Overflow  Terminates acquisition when any channel exceeds 2 billion.

Peak Uncertainty

Nuclide MDA

MULTIPLEXER/ROUTER

Inputs  One to 16, software selectable.

Signal Isolation  Typically >72 db rejection of unselected inputs.

Input Threshold  Set by front-panel screwdriver adjustment. Range is from 100 to 500 mV and is common to all inputs.

Gain  Nominally unity.

DC Level Instability  ≤20 µV/°C.

Integral Linearity  0.05%.

Gain Instability  50 ppm/°C.

FRONT-PANEL INDICATORS

CPU BUSY  Red LED’s intensity indicates the relative activity of the microprocessor.

MUX BUSY  Red LED’s intensity indicates the relative activity of the multiplexer/router.

ADC BUSY  Red LED flashes once for each pulse digitized by ADC.

CONTROLS

MUX DISC  Screwdriver potentiometer from 100 to 500 mV.

ADC ZERO  Screwdriver potentiometer adjusts the ADC zero offset ±250 mV.

ADC LLD  Screwdriver potentiometer adjusts the lower level discriminator from 0 to 50% of full scale.

INPUTS

INPUT 1  Front-panel BNC accepts positive unipolar, positive gated integrator, or positive-leading bipolar, +10 V, pulse; +12 V maximum; semi-Gaussian-shaped or gated-integrator-shaped time constants of 0.50 to 30 µs. Z_in = 1000 Ω, dc-coupled. No internal delay.

AMPLIFIER INPUTS  Accepts positive unipolar, positive gated integrator, or positive-leading bipolar +10 V; +12 V maximum; semi-Gaussian-shaped or gated-integrator-shaped time constants of 0.50 to 30 µs. Z_in = 1000 Ω, dc-coupled. No internal delay. Inputs 1 to 16 are on rear-panel, 50-pin Amplifier Input connector. Optional cable (920-16-OPT1) converts 50-pin D connector to multiple BNCs.

ADC GATE  Optional, slow positive NIM input. Computer-selectable Coincidence or Anticoincidence. Signal must occur prior to and extend 0.5 µs beyond peak of input pulse. Front-panel BNC connector. Gate control for all active inputs.

INTERFACES⁴

ETHERNET  Rear-panel BNC connector, accepts IEEE 802.3 10BASE2 (thin-wire coax).

ELECTRICAL AND MECHANICAL

POWER REQUIRED  +24 V, 165 mA; –24 V, 165 m A. +12 V, 160 mA; –12 V, 110 mA;  +6 V, 1.2 A.

WEIGHT
Net  2.25 kg (5 lb).
Shipping  3.1 kg (7 lb).

DIMENSIONS  NIM-standard double-width 6.90 X 22.13 cm (2.70 X 8.714 in.) front panel per DOE/ER-0457T.

ORDERING INFORMATION

³Ron Jenkins, R.W. Gould, and Dale Gedcke, Quantitative X-Ray Spectrometry (New York: Marcel Dekker, Inc.), 1981 pp 266–267.

⁴The following connectors are also available:
Dual-Port Memory — ORTEC dual-port interface, 37-pin D connector.
RS-232-C — Serial standard RS-232-C 25-pin; male wired as DTE to run at 38.4k baud maximum, with modem control. Software selectable baud rate. (For diagnostics)