Keithley 2016 - Sdc (Selective Device Clear); Get (Group Execute Trigger); Spe, Spd (Serial Polling)

When the Model 2016 THD Multimeter receives a DCL command, it clears the Input Buffer
and Output Queue, cancels deferred commands, and clears any command that prevents the
processing of any other device command. A DCL does not affect instrument settings and stored
data.
Program fragment
PRINT #1, "clear" 'Clear all devices
SDC (selective device clear)
The SDC command is an addressed command that performs essentially the same function as
the DCL command. However, since each device must be individually addressed, the SDC
command provides a method to clear only selected instruments instead of clearing all
instruments simultaneously, as is the case with DCL.
Program fragment
PRINT #1, "clear 16" 'Clear 2016
GET (group execute trigger)
GET is a GPIB trigger that is used as an arm, scan and/or measure event to control operation.
The Model 2016 THD Multimeter reacts to this trigger if it is the programmed control source.
The control source is programmed from the SCPI: TRIGger subsystem.
With the instrument programmed and waiting for a GPIB trigger, the following program
fragment will provide the GET:
Program fragment
PRINT #1, "trigger 16" 'Trigger 2016 from over the bus
This sends IEEE-488 commands UNT UNL LISTEN 16 GET. When the command is
executed, the trigger event occurs. (The command TRIGGER just sends GET. Any other
listeners are triggered when the command is executed.)
SPE, SPD (serial polling)
Use the serial polling sequence to obtain the Model 2016 serial poll byte. The serial poll byte
contains important information about internal functions (see “status structure”). Generally, the
serial polling sequence is used by the controller to determine which of several instruments has
requested service with the SRQ line. However, the serial polling sequence may be performed at
any time to obtain the status byte from the Model 2016 THD Multimeter.
Program fragment
PRINT #1, "spoll 16" 'Serial poll the 2016
INPUT #2, S 'Read serial poll byte
PRINT S 'Display the decimal value of
the serial poll byte
4-14 Remote Operation