HP E1368A manual Scanning Channels, Selects the Trigger Source

Scanning Channels

Scanning the Microwave Switch module channels consists of closing a set of channels (connecting the 2 port to the C port) one channel at a time. Single scan, multiple scans (2 to 32767), or continuous scanning modes are available.

The TRIGger:SOURce command specifies the source to advance the scan.

The OUTPut command can be used to enable the HP E1300/E1301 or HP

E1405/E1406 "Trig Out" port. Figure 3-8 illustrates the scanning sequence.

Sets number of Scanning Cycles

ARM:COUN <number> sets 1 to 32767 scanning cycles per INIT command.

Selects the Trigger Source

TRIG:SOUR defines the trigger source to advance the scan.

TRIG:SOUR? queries the current trigger source. Sources are:

BUS = Defines trigger source as a *TRG or HP-IB GET command executed over the HP-IB. With TRIG:SOUR BUS, the scan list is advanced for each *TRG or GET command received.

EXT = TRIG:SOUR EXT sets external triggering. The trigger source is a (user supplied) input to the Event In BNC. Use a +5 V Negative-going pulse to trigger.

HOLD = Prevents execution of triggers until trigger source is changed.

Can use TRIG command to trigger a switchbox set to TRIG:SOUR HOLD.

IMM = Sets immediate (internal) triggering. The scan list is automatically advanced through the scan list. This is the default trigger mode.

Enables TRIG OUT Port

The Trig Out Port is shared by all instruments in the mainframe. With the port enabled (OUTP ON), it generates an output trigger each time after a channel closure for ANY switchbox in the mainframe. The Trig Out port outputs a +5 V negative-going pulse.

Selects Continuous Scanning Cycles

Use INIT ON or INIT 1 to enable continuous cycles. INIT OFF or INIT 0 is fixed number of scans determined by the ARM:COUN command.

Selects the Channel List for Scanning

SCAN <channel_list> defines channels to be scanned using trigger source by TRIG:SOUR command.

Enables Scanning

Enables scanning for any trigger source and closes the first channel in

the channel list.

Advances Channel List

This command advances the channel list when the trigger source is

TRIG:SOUR BUS or TRIG:SOUR HOLD. Command not usable with

TRIG:SOUR EXT or TRIG:SOUR IMM.

Figure 3-8. Example: Scanning Commands

Chapter 3 Using the HP E1368A/69A/70A Modules 39