If convergence is achieved within two minutes, the new pole/zero value can
be verified as indicated in step 3 above. If the pole/zero was unsuccessful, an
error message will be posted in the error dialog box.
4.
Unsuccessful Pole/Zero and Error Messages
If the Auto Pole/Zero operations fails to converge when initiated one of the
following messages will be displayed in the error dialog box to provide
diagnostic information regarding the problem. The error message can be
cleared by clicking on Ok in the error dialog box.
a.
Pole/zero not possible with TRP
You have attempted to initiate an Auto P/Z operation with the Genie
environment and hardware configured for a TRP detector; that is, a
detector fitted with a reset type preamp. The Auto P/Z function is dis-
abled when a TRP preamp is selected. If you are using a detector with
an RC preamp, please go to the MID Editor and set the Preamp Type
to “RC”.
b. Pole/zero failed to converge
This message may result from any of the following reasons:
P/Z Time Out Error
– The Auto P/Z has failed to complete within a
maximum time of two minutes. The preamp fall time could be outside
the 40
µ
s to 1.7 ms pole/zero adjustment range or the incoming count
rate (ICR) is below 1 kHz. The Auto Pole/Zero will not converge
properly if the ICR is less than 1 kHz. Additional causes may be
excessive noise or abnormal variations of the Trapezoid baseline. This
could result from excessive detector microphonics, high voltage
arcing in the detector or preamp, secondary preamp signal time
constants or a damaged detector. For those cases, P/Z compensation
must be performed manually. Please refer to “Manual Pole/Zero
Matching” on page 41.
The Incoming Count Rate is Too High
– The incoming count rate
(ICR) exceeds 20 kHz. The Auto Pole/Zero will not converge properly
if the ICR exceeds 20 kHz. For this condition, the error message will
be posted very quickly; long before the two minute time out.
Chapter 6 - Setup and Operation
40
Model 9660-9660A ICB Digital Signal Processor