Agilent Technologies 75000 SERIES B Output 722TRIG Extdcvmem Fifo, Output 70914TRIGSOUR EXT

Example: Synchronizing an Internal Instrument to an External Instrument

This example uses the mainframe’s Trig Out and Event In ports to synchronize an external multimeter to a multiplexer installed in the mainframe. Connections are shown in Figure 4-3. The multimeter’s Voltmeter Complete port outputs a pulse whenever the multimeter has finished a reading. The multimeter’s External Trigger port allows the multimeter to be triggered by a negative going TTL pulse. Since the synchronization is independent of the GPIB bus and the computer, readings must be stored in the multimeter’s reading memory. The sequence of operation is:

1.INIT (line 50) closes channel number 100.

2.The channel closure causes a pulse on Trig Out which triggers the multimeter to take a reading.

3.When the reading is complete it is stored in multimeter memory and the multimeter outputs a pulse on its Voltmeter Complete port. This signals the multiplexer to advance to the next channel in the scan list.

4.Steps 2 and 3 are repeated until all channels have been scanned and readings taken.

10 OUTPUT 722;"TRIG EXT;DCV;MEM FIFO"

Set multimeter to external trigger, DC volts, enable reading memory

20 OUTPUT 70914;"OUTP ON"	Enable Trig Out port
30 OUTPUT 70914;"TRIG:SOUR EXT"	Set multiplexer to advance scan
	on external signal
40 OUTPUT 70914;"SCAN (@100:115)"	Specify scan list (channels 100
	to 115)
50 OUTPUT 70914;"INIT"	Close first channel (starts
	scanning cycle)
60 END

Example: Synchronizing Internal/External Instruments and the Computer This

example uses the mainframe’s Trig Out port to synchronize an external

Figure 4-3. Synchronizing Internal/External Instruments

4-4 Using the Mainframe