HP 8560E Service Manual page 309

General Troubleshooting
System Analyzer Programming Errors (100 to 150)
During the LO adjust sequence, the main roller is
locked and then programmed to a frequency 1.6 MHz
higher. A new pretune DAC value is calculated based
upon the main roller tuning sensitivity. ERR 322 is set
if this calculated value is greater than 255. This error is
not applicable to HP 8560 E-series or EC-series
spectrum analyzers. If it occurs in an HP 8560 E-series
or EC-series spectrum analyzer, suspect a problem with
the model number identification in the spectrum
analyzer firmware.
324 FREQ ACC Unable to adjust MAINSENSE close to 0 volts using
the coarse adjust DAC. The coarse adjust and fine
adjust DAC are used together to set MAINSENSE to 0
volts with the loop opened. ERR 324 is set if the coarse
adjust DAC cannot bring MAINSENSE close enough to
0 volts for the fine adjust DACs to bring MAINSENSE
to exactly 0 volts. This error is not applicable to HP
8560 E-series or EC-series spectrum analyzers. If it
occurs in an HP 8560 E-series or EC-seriesHP 8560
E-series or EC-series spectrum analyzer, suspect a
problem with the model number identification in the
spectrum analyzer firmware.
325 FREQ ACC Unable to adjust MAINSENSE to 0 volts using the fine
adjust DAC. The coarse adjust and fine adjust DAC are
used together to set MAINSENSE to 0 volts with the
loop opened. ERR 325 is set if the fine adjust DAC
cannot bring MAINSENSE to 0 volts. This error is not
applicable to HP 8560 E-series or EC-series spectrum
analyzers. If it occurs in an HP 8560 E-series or
EC-series spectrum analyzer, suspect a problem with
the model number identification in the spectrum
analyzer firmware.
326 FREQ ACC Fine adjust DAC near end of range. The fine adjust
DAC is set to bring MAINSENSE to 0 volts. ERR 326 is
set if the fine adjust DAC value is set to less than 5 or
greater than 250. This error is not applicable to HP
8560 E-series or EC-series spectrum analyzers. If it
occurs in an HP 8560 E-series or EC-series spectrum
analyzer, suspect a problem with the model number
identification in the spectrum analyzer firmware.
327 OFF UNLK Offset roller oscillator PLL is unlocked. May indicate
loss of 10 MHz reference. The 10 MHz reference should
measure greater than −7 dBm at A15J303. The ADC
measures OFFSENSE at the beginning of each sweep
and, if the voltage is outside certain limits, the offset
oscillator pretune DAC is adjusted to bring OFFSENSE
within the proper range. ERR 327 is set if this cannot
308 Chapter 6