When you are using the multichannel function, the PWX that communicates with the PC is the VMCB master unit.
To configure a PWX that you are using with the multichannel function, you first have to specify the channel of the PWX that you want to configure.
At power on, the PWX is set to channel 0.
First specify the channel, and then configure the other settings.
Setup example for a PWX that you set to channel 2:
:INST:NSEL 2 'Specify channel 2.
:VOLT 12.0 'Set the channel 2 voltage to 12.0 V.
:CURR 1.5 'Set the channel 2 current to 1.5 A.
You can use the GLOBal subsystem to make changes to the settings (voltage, current, turning output on or off) of all channels at the same time. Insert a wait of at least 200 ms after sending a GLOBal subsystem command.
:GLOB:VOLT 20 'Set the voltage of all channels to 20 V.
:GLOB:CURR 2 'Set the current of all channels to 2 A.
:GLOB:OUTP 1 'Turn output on for all channels.
The GLOB:OUTP command turns on/off the output of all configured channels, but they are not turned on/off at the same time. There is a slight time offset between channels.
You can configure changes to settings on the PWXs in advance, and then use triggers to synchronize the changes on all units. The INIT and TRIG commands are sent to all channels.
:INST:NSEL 0 'Specify channel 0.
:TRIG:TRAN:SOUR BUS 'Set the trigger source of channel 0 to BUS.
:VOLT:TRIG 10;:CURR:TRIG 10
'Configure channel 0 so that the voltage will be set to 10 V and the current to 10 A when a trigger occurs.
:INST:NSEL 1 'Specify channel 1.
:TRIG:TRAN:SOUR BUS 'Set the trigger source of channel 1 to BUS.
:VOLT:TRIG 20;:CURR:TRIG 20
'Configure channel 1 so that the voltage will be set to 20 V and the current to 20 A when a trigger occurs.
:INIT:TRAN 'Initiate the measurement.
:TRIG:TRAN 'Apply a software trigger.
When you send the TRIG command, the settings of channel 0 and channel 1 are changed.
The OPERation Status register is used to record events and notifications that occur during normal operations.
To check whether CV output is being performed, check the CV bit (bit 8) of the OPERation:INSTrument:ISUMmary<n> subregister.
:STAT:OPER:INST:ISUM2? 'Check whether the CV bit of channel 2 is set.
The QUEStionable Status register is used to record events and notifications that occur during abnormal operations.
To check whether the overvoltage protection function has been activated, check the OV bit (bit 0) of the STATus:QUEStionable register.
:STAT:QUES? 'Check whether the OV bit is set.
Even if bit 0 is true, you can not tell on which channel the overvoltage protection function has been activated. To check which channel is operating abnormally, check the STATus:QUEStionable:INSTrument subregister.
:STAT:QUES:INST? 'Check which channel is operating abnormally.
All channels whose corresponding bits are true are operating abnormally. You can determine how the specified channel is operating abnormally by checking the STATus:QUEStionable:INStrument:ISUMmary<n> subregister of the channel.
:STAT:OPER:INST:ISUM2? 'Check whether the OV bit of channel 2 is set.