Example: Scanningwith ExternalInstruments

This example uses the mainframe "Trig Out" port to synchronize the multiplexers to an HP 3457A Digital Multimeter. See the following figure for typical connections. For this example, use the trigger output pulse of the mainframe "Trig Out" port to trigger the multimeter from its "External Trigger" port.

The sequence of operation is:

1.INIT (line 70) closes channel number 100.

2.The channel closure causes a trigger output from the "Trig Out" port.

3.The trigger causes the multimeter to make a measurement.

4.Measurement result is sent to the computer (lines 80 to 100).

5.TRIGGER command (line 110) advances the channel list to the next channel.

6.Steps 2-5 are repeated for channels 101 through 115.

10

OUTPUT 722;"TRIG EXT;DCV"

!Sets multimeter to external trigger

 

 

and to measure dc volts

20

OUTPUT 70914;"OUTP ON"

!Enables "Trig Out" port

30OUTPUT 70914;"TRIG:SOUR BUS" !Sets switchbox to receive bus triggers

40OUTPUT 70914;"SCAN:MODE VOLT"!Sets switchbox to measure voltage

50OUTPUT 70914;"SCAN:PORT ABUS"!Closes the tree isolation switches

60OUTPUT 70914;"SCAN (@100:115)" !Selects the channel list for scanning

70

OUTPUT 70914;"INIT"

!Starts scanning cycle

80

FOR I = 1 TO 16

!Start count loop

90

ENTER 722;A

!Enter reading into variable A

100

PRINT A

!Print reading in variable A

110

TRIGGER 70914

!Trigger the switchbox to advance

 

 

the channel list

120

NEXT I

!Increment count

130

END

 

48 Understanding the HP E1351A/53A FET Multiplexer Modules

Chapter 4