48    Sequoia Series 
 
4.3  Instrument Subsystem 
The Instrument subsystem controls the phase mode of the power source for configurations capable of 
operating in three phase mode. 
Subsystem Syntax 
INSTrument 
  COUPle ALL | NONE  Couples or uncouples commands 
  :NSELect 1 | 2 | 3  Selects phase A, B or C using numeric references 
  :SELect A | B | C  Selects phase A, B or C using character references 
INSTrument:COUPle 
This command may be used to couple all output phase in three phase mode. When the phases are 
coupled, commands issues subsequently affect all three phases. This allows the output voltage to be 
programmed for all three phases using a single command and without the need to select each phase 
individually. When uncoupled, commands issued must be preceded by the PHAS:NSEL command 
and will only affect the selected command. 
Available parameters are ALL to couple all phases and NONE to uncouple all phases. In single phase 
mode, the INST:COUP commands are ignored. 
Command Syntax  INSTrument:COUPle 
Parameters  ALL | NONE 
Examples  INST:COUP ALL 
Query Syntax  INST:COUP? 
Returned Parameters  <CRD> 
Related Commands  INST:NSEL  INST:SEL 
INSTrument:NSELect 
This command may be used select a specific output phase in three phase mode using a numeric 
reference. A 1 denotes phase A, a 2 denotes phase B and a 3 denotes Phase C. As long as the 
instrument state is coupled however, programming command will affect all phases. As soon as the 
INST:COUP NONE command is issued, the last selected phase becomes selected. To immediately 
change the output of a single phase only, make sure the instrument state is uncoupled when issuing 
the INST:NSEL command. 
Note that the MEASure and FETCh subsystems are not affected by the INST:COUP command and 
always operate on the selected phase only. This means the instrument can remain in coupled mode 
while doing measurement queries using “INST:NSEL  <n>;FETC:VOLT?;*WAI”. Note that when 
the instrument is subsequently put in the uncoupled state using “INST:COUP NONE”, the last issued 
phase selection will be in effect. To make sure the desired phase is selected, follow the “INST:COUP 
NONE” command with an “INST:NSEL <n>” command 
Command Syntax  INSTrument:NSEL 
Parameters  1 | 2 | 3 
Examples  INST:NSEL 1 
Query Syntax  INST:NSEL? 
Returned Parameters  <CRD> 
Related Commands  INST:COUP  INST:SEL