HP 8901B Operation And Calibration Manual page 335

Model 8901B Operation
Error Message Summary
DESCRIPTION
Error Messages are one means the Modulation Analyzer uses to safeguard measurement integrity.
When the instrument senses a potential error-causing situation, an Error Message code is displayed to
alert the user of the condition. The Error Message code indexes an Error Message which describes the
current error. Error Messages indicate operating problems, incorrect keyboard entries, or service-related
problems. The error message is usually cleared when the error condition is removed.
Two types of error message display formats are used
Error NN: The numerical value (NN) of the error message is displayed and
-
- No detectable signal falls within the IF' passband. Either no signal is at the input, or the
instrument cannot tune to find the applied signal. (For example, it might be manually tuned far
enough away from an input signal that no power is detected in the IF'.) This display is output to
the HP-IB as Error 96 using the HP-IB output format described in "HP-IB Output Format".
- - - - A signal has been detected but, for various reasons, a measurement result is not yet
available. The instrument might be still completing the measurement requested, or in some cases,
unable to complete a measurement because of manual settings of special Wctions. (For example,
when frequency measurements are made on a low-level input signal with high AM depth, or when
the RF input attenuation is improperly set.) This display is never output
to
the HP-IB and
typically indicates a transitory state in instrument operation.
Error messages are grouped by error code as follows:
Errors 01 through 19 and 90 through 99
These messages are Operating Errors which indicate a condition has not been met to assure a calibrated
measurement. Operating Errors can usually be cleared by readjustment of front-panel controls (usually,
the easiest way is to select AUTOMATIC OPERATION). The DISABLE ERROR key or Special
Function 8 can be used to selectively disable Errors 01 through
04.
(Refer to Error Message Disable
Control on page 3-233.)
Errors 20 through 29
These messages are Entry Errors which indicate an invalid key sequence or keyboard entry. These
errors require that a new keyboard entry or function selection be made. Some of these error displays
time out after a few seconds and then allow the display
to
return to the current measurement.
Errors 40 through 89
These messages are Service Errors generated to provide service-related information. They must be
enabled to be displayed since they are not displayed in normal instrument operation. Service Error
Messages are discussed in Section 8 of the Service Manual.
Error Message Summary
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