Example: Scanning
with External
Instruments
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
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 |
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48 Understanding the HP E1351A/53A FET Multiplexer Modules | Chapter 4 |