Example: Scanning Channels

This example uses the mainframe’s "Trig Out" port to synchronize Microwave Switch channel 00 to 02 closures to an external measurement device (e.g. Frequency Counter, Spectrum Analyzer). For measurement synchronization, the HP E1300A/E1301A "Trig Out" port is connected to the external instrument’s "EXT Trig In" port.

Figure 3-9 shows how to connect the Microwave Switch module to the external instrument. The mainframe and external instrument are connected to the computer’s HP-IB port, and the measurement results are transferred directly to the computer. For the example, use:

an HP-IB select code of 7, primary address of 09, and secondary address of 15 for the Microwave Switch

an HP-IB select code of 7, primary address of 22 for the External Instrument

an HP Series 200/300 Computer with HP BASIC

Execute:

10

OUTPUT 722;"TRIG EXT;"

!Configures the external

 

 

instrument. Appropriate instrument

 

 

commands must be added to make

 

 

the measurement.

20

OUTPUT 70915;"*RST"

!Opens all channels, resets

 

 

Microwave Switch module to

 

 

known state.

30

OUTPUT 70915;"OUTP ON"

!Enable "Trig Out" port.

40OUTPUT 70915;"TRIG:SOUR BUS" !Sets trigger source to bus triggering.

50OUTPUT 70915;"SCAN (@100:102)" !Defines channel list to scan channels 00, 01, and 02.

60

OUTPUT 70915;"INIT"

!Closes channel 00 and enables the

 

 

scan. Causes a trigger output from

 

 

mainframe’s "Trig Out" port which

 

 

initiates the external instrument to

 

 

make a measurement.

70

FOR I=1 to 3

!Start counting loop (3 channels).

80

WAIT 1

!Allows external instrument time to

 

 

settle and make measurement.

90

ENTER 722;A

!Enters measurement result.

100

PRINT A

!Displays measurement result.

110

TRIGGER 70915

!Advance scan to channel 01 (then

 

 

02).

120

NEXT I

!Increment the count and repeats

 

 

measurement process for a total of

 

 

three measurements (channels 00,

 

 

01, and 02).

130

END

!Terminate program.

40 Using the HP E1368A/69A/70A Modules

Chapter 3

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HP E1368A manual Example Scanning Channels, Output 722TRIG EXT …