HP 8642A Operation And Calibration Manual page 233

Model 8642A/B Operation
Operating Messages (cont'd)
Out-oi-Lock Messages. The following messages are out-of-Iock messages that might appear as queued
up messages during operation. (These messages will be disabled if Special Function 119, Disable Settling, is
selected) If any of these messages occur, the instrument might not be functioning properly and need to be
serviced. However, some of t he messages might be displayed because you have exceeded the instrument's
limits. The out-of-Iock messages are listed in the Table 3-29, Out-of-Lock Messages on the following
page. The solution column provides the number(s) of the solution(s) listed below that might eliminate the
out-of-Iock condition. IF THE PRESCRIBED SOLUTION DOES NOT ELIMINATE THE MESSAGE,
THE INSTRUMENT SHOULD BE SERVICED.
Also, these messages can be output using "OH". Refer to the Output Messages discussion that begins on
page 3 -16 in the HP- IE
portion
of this
Section
III and to Hardware Error Messages on page 3-193.
Solutions
1.
Either reduce the amplitude level,
reduce the AM depth, or
reduce the external modulation input level.
2. Either reduce the FM or .pM deviation,
reduce the modulation frequency,
select Special Function 8 (Prefer Heterodyne Band),
change the external modulation rate, or
change the external modulation level.
3. Either the external reference is not operating properly or
connections are faulty at the rear-panel connector, EXT REF INPUT. (The internal hardware may
still be faulty even though the message is gone; that is, the message would appear again If you
connected another external reference to the instrument.}
3-197