Appendix A
Model 8642A/B
Appendix A: Glossary (cont'd)
heterodyne band
The heterodyne band covers the same frequency range as divide bands 1 through 6, but the
heterodyne band allows wider FM and $M deviation and wider frequency spans for Phase
Continuous Frequency Sweep. Refer to RF Frequency, page 3-39,
last-selected value
A function's last-selected value usually can be toggled on with the [ OFF OTNTI key.
power up
When the instrument is powered up, it goes through a sequence of internal checks. Refer to
Instrument Preset, Partial Preset, page 3-137.
queued up
A queued up list is a list of messages that can be accessed when the
1
MSS(J~) key is pressed again
and again. The MSSG annunciator will indicate when a message is queued up for display. Refer
to "Queued Up Messages" on page 3-180.
RQS
RQS (request service) is from the Signal Generator's point of view. The request service (RQS) bit
is in the 8642A/B Status Byte. This bit affects when the service request (SRQ) line is pulled on
the HP-JB interface. Refer to page 3-27.
scroll
Scrolling through the Help function list lets you view the description and code number of each
Special Function. (Refer to the Special Functions, page 3-167.) You can scroll through the
message list by repeatedly selecting the [ MSSGl key.
SRQ
SRQ is from the HP-IB controller's point of view. The service request (SRQ) line is a signal line
on the HP-IB interface. This line is pulled low by the Signal Generator when it is requesting
service. Refer to page 3-27.
The SRQ annunciator in the display of the 8642A/B indicates that this Signal Generator is
pulling the HP-IB SRQ line low.
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