Agilent Technologies E5100A, Programming Manual, Page: 74 / 373

SRQ and Interrupt
Y ou can initialize your program to enable interrupt processing by the Service Request (SRQ)
from the analyzer . The analyzer generates an SRQ when the specied condition is satised.
The SRQ itself does not contain information on the SRQ source . However , the Request Service
(RQS) bit in the Status Byte Register of the SRQ source device is set to 1. If multiple devices
are connected on the bus , you can check the RQS bit (bit 6) of the analyzer by using a serial
poll, SPOLL.
Use the SRQ interrupt if you want to determine when the condition changes . The following
procedure is used to set the SRQ interrupt:
1. Dene the branch for the interruption. (Use ON INTR statement.)
2. Set the enable register for the corespondent event register bit to 1.
3. Set the service request enable register bit for the correspondent status byte register bit to 1.
4. Clear the status register before enabling the SRQ interruption.
5. Enable the SRQ interruption. (Use ENABLE INTR statement.)
6. Start the event.
7. W ait for the SRQ. Usually , the program waits within an endless loop .
8. If multiple devices that can generate an SRQ exist on the GPIB , you should check bit 6 of
the status byte register of the target device . If the SRQ is generated from the target device ,
the status byte register bit 6 is set to 1.
The following example uses an SRQ interruption for detecting the end of sweep . Bit 0 of the
instrument event status register is used for this purpose .
ON INTR Scode GOTO Sweep_end When the SRQ has occurred, jumps to label, \Sweep end."
OUTPUT @E5100;"ESNB 1" Set bit 0 of the instrument event status enable register to 1. (2
0
=1)
OUTPUT @E5100;"*SRE 4" Set bit 2 of the service request enable register to 1. (2
2
=4)
OUTPUT @E5100;"*CLS" Clears the event register .
OUTPUT @E5100;"*OPC?" Conrms the clear operation is completed.
ENTER @E5100;Opc
!
OUTPUT @E5100;"HOLD" Sets the trigger mode HOLD .
ENABLE INTR Scode;2 Enables the SRQ interruption just before triggering.
OUTPUT @E5100;"SING" Trigger a measurement.
Waiting: GOTO Waiting W aits until SRQ is generated.
Sweep_end:! When on SRQ, program jumps to this label.
IF NOT BIT(SPOLL(@E5100),6) THEN Check the SRQ is generated from the target device by checking status
byte register bit 6.
ENABLE INTR Scode;2 If not, enable the SRQ again, then
GOTO Waiting returns to the endless looping.
END IF
Module 4-2. Detecting Sweep End Using SRQ and Interrupt
Note
*CLS clears only the event registers and the status byte register . The enable
register and transition lter settings are not altered by executing the *CLS
command. T o clear the enable register and transition lter , use the PRES
command.
Figure 5-7 shows the SRQ generation sequence of the example above .
5-10 Using Status Reporting Function