Table of Contents
Advertisement
APPENDIX D
Lines 10 and 20:
Lines 70 to 90:
Line 100:
Lines 130 to ZOO:
Line 130:
Line 140:
Line 150:
Lines 160 to 180:
Lines 200 and 210:
Lines 220 to 250:
SERVICE REQUEST FROM THE FRONT PANEL
When the spectrum analyzer is in local operation mode (unaddressed), the operator can call for service from a
controller by pressing front panel key [SHIFT r]. This front panel request for service sends SRQ 102, the units-key-
pressed SRQ. The SRQ command, R4, need not be enabled in order to use the front panel service request.
Example
The front panel service request can summon a controller for assistance. The following example shows one way to
do this. During the data transfer, beginning at line 430, the CRT display appears as shown below, with the "DATA
TRANSFER" message blinking.
Several analyzers, each with a different HP-IB address, can call for individual service. This requires serial polling at
the beginning of the service subroutine.
Executes the "Read-entry" subroutine when an interrupt at select code 7 occurs.
Enables interrupts from the HP-IB interface card.
Any main program.
Disables the R4 service request.
Forms a subroutine that records the operator's entry.
Turns off interrupts from the HP-IB interface.
Clears the end-of-sweep SRQ and reads the status byte.
Checks the status byte to verify that the interrupt was caused by the units-key-pressed
SRQ. If this is not the case, the program continues at line 220.
Reads the operator's entry and displays it.
Re-enables operator entry, units-key-pressed SRQ, and the controller interrupt capabil-
ity.
Notifies the operator if the illegal analyzer command SRQ triggered the interrupt.
SERVICE REQUESTS
A p p e n d i x 3 9
Advertisement
Table of Contents
