Offset - Offsets the spectrum to the left; subtracts 0 to 16 256 channels in binary
multiples of 128 channels.
LLD - Digital Lower Level Discriminator for minimum input acceptance level;
adjustment range 0.0% to 100% of the spectrum full scale range.
Zero Adjust - Digital Zero Adjustment;
±
3.13% of the spectrum full scale range.
FDisc Mode - AUTO, MANUAL; AUTO: Fast Discriminator (FD) threshold is
optimized automatically; MANUAL: Fast Discriminator signal is over a range of
0 to 100%.
FDisc Setting - Allows adjustment of the Fast Discriminator threshold level
when MANUAL DISC THRES is selected. The adjustment range is 0% to
100%; also serves as a user aid when manually setting the Fast Discriminator.
LT Trim - Allows adjustment of the trapezoid pulse evolution time or dead time
to optimize Live Time Correction (LTC) performance. The adjustment range is 0
to 1000; the default value of 250 provides good LTC performance for a wide
range of applications.
LTC Mode - ON, OFF, LFC
ON: Enables pile-up rejector and live time corrector (LTC). LTC generates
dead time to extend the acquisition time to compensate for events that are
piled-up and rejected.
OFF: Pile-up rejector and LTC disabled.
LFC: Enables pile-up rejector and LFC interface, LTC function disabled;
when used with Model 599 LFC Module counting losses are corrected in real
time.
PUR GUARD - NORM, ADJUST; Selects guard time multiplier “GT” in
increments of 1.1, 1.3, 1.5, 1.7, 1.9, 2.1, 2.3 and 2.5 to reject trailing edge pile up
in the event of detector/preamp anomalies; guard time extends from peak detect
time by the amount (GT x T
R
+ T
FlatTop
); “GT=1” selects minimum resolving
time for maximum throughput.
Inh Polarity - Selects either POSITIVE or NEGATIVE inhibit polarity.
Inp Polarity - Selects either POSITIVE or NEGATIVE input polarity.
Inhibit Mode - Selects either NORM or RESET inhibit modes; with NORM
selected, the system is gated off while external INHIBIT is set true. In RESET
Appendix A - Specifications
58
Model 9660-9660A ICB Digital Signal Processor
