HP E1366A, E1367A manual Using the Scan Complete Bit, Example Scan Complete Interrupt

Models: E1367A E1366A

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Using the Scan Complete Bit

You can use the Scan Complete Bit (bit 8) in the Operation Status register of a switchbox to determine when a scanning cycle completes (no other bits in the register apply to the switchbox). Bit 8 has a decimal value of 256 and you can read it directly with the STAT:OPER? command. Refer to STATus:OPERation[:EVENt]? command in Chapter 5 for an example.

When enabled by the STAT:OPER:ENAB 256 command, the Scan Complete Bit will be reported as bit 7 of the Status register. Use the HP-IB Serial Poll or the IEEE 488.2 Common Command *STB? to read the Status register.

When bit 7 of the Status register is enabled by the *SRE 128 Common Command to assert an HP-IB Service Request (SRQ), you can interrupt the computer when the Scan Complete Bit is set, after a scanning cycle completes. This allows the controller to do other operations while the scanning cycle is in progress.

The following example monitors bit 7 in the Status register to determine when the scanning cycle completes. The computer used in this example is an HP 9000 Series 200/300 used with HP BASIC as the programming language. The computer interfaces with an HP E1300A/E1301A mainframe over HP-IB. The HP-IB select code is 7, the HP-IB primary address is 09, and the HP-IB secondary address is 15.

Example: Scan

Complete Interrupt

10 OUTPUT 70915;"*CLS"

! Clear all switchbox status structure

20OUTPUT 70915;"STAT:OPER:ENAB 256" ! Enable Scan Complete Bit to set bit 7 in Status register

30

OUTPUT 70915;"*SRE 128"

! Enable bit 7 of Status register to

 

 

assert SRQ

40

OUTPUT 70915;"TRIG:SOUR EXT"

! External trigger mode

50

OUTPUT 70915;"SCAN (@100:105)"

! Select channels to be scanned

60

OUTPUT 70915;"INIT"

! Start scanning cycle

70

WHILE NOT BIT(SPOLL(70915),7)

! Waiting for scan complete

80PRINT "DO OTHER OPERATION HERE" ! Enter program lines for computer to do other operations

90 END WHILE

100PRINT "INTERRUPT GENERATED" ! Program goes to this line after interrupt generated by a completed scanning cycle

110 END

36 Understanding the HP E1366A/E1367A RF Multiplexers

Chapter 4

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HP E1366A, E1367A manual Using the Scan Complete Bit, Example Scan Complete Interrupt