ICR (Incoming Count Rate) - Provides a standard TTL logic signal; frequency corre-
sponds to input count rate; positive true; width
≈
150 ns, Z
out
≈
50
Ω
; rear panel BNC
connector.
DATA - Provides 14 binary TTL-compatible output lines and the data transfer com-
mands required for MCA interface; data interface is compatible with the Canberra
Model 556/556A Acquisition Interface Module (AIM), rear panel 34-pin ribbon cable
connector.
DT/BSY - Rear panel BNC with two functions: Dead Time or Busy, selected by LTC
Mode; TTL output with 47
Ω
series resistor; rear panel BNC connector.
Front Panel Indicators
READY - Indicates operational status. Bi-color LED: green when on-line, yellow for
fault or error, off when the module is waiting computer recognition.
BDC BUSY - Green LED, monitors status of AUTO BDC (Ballistic Deficit Correc-
tion) matching function, ON continuously while trapezoid flat top is automatically
matched to the charge collection time of the detector, OFF when proper matching is
achieved, active only when AUTO BDC mode is enabled.
ICR - Green LED indicator, blinks for every input event detected by the Fast
Discriminator; intensity corresponds to input count rate.
ICB Programmable Controls
The programmable controls are grouped by the associated device adjust menu.
Gain Device Adjust Menu
System gain is continuously variable from x2.0 to x1536.
Coarse Gain - x5, x15, x40, x120, x330, x960.
Fine Gain - Range: x0.4 to x1.6.
S-FINE Gain (SFG) - Range: 0.0000e
–2
to 3.000e
–2
; the SFG adds to the FINE
Gain Value; resolution is better than 1 part in 16 000.
Conv Gain - Selections of 256, 512, 1024, 2048, 4096, 8192, or 16 384 channels.
Represents the full scale resolution of the input signal. Conversion range is set to
equal the selected conversion gain.
User’s Manual - ICN 9231014G
57
Front Panel Indicators
