5.13. SOURce

SCPI command

Description

[SOURce[<n>]]

:CURRent

[:LEVel]

[:IMMediate][:AMPLitude] {<current>}

Sets the output current

:STEP[:INCRement] {<step>}

Sets the step of the current change

:TRIGgered[:AMPLitude] {<current>}

Sets the triggered output current

:LIMit

[:POSitive][:IMMediate][:AMPLitude] {<current>}

Sets the output current limit

:MODE {<mode>}

Sets the current trigger mode

:PROTection

:DELay

[:TIME] {<time>}

Sets the over-current protection (OCP) programming delay

:STATe {<bool>}

Enables/disables over-current protection on the selected channel

:TRIPped?

Returns status of over-current protection activation

:SLEW

:FALLing

Sets the falling current slew rate

:RISing

Sets the rising current slew rate

:LIST

:COUNt

Sets the number of times that the list is executed

:CURRent[:LEVel]

Specifies the current setting for each list step

:DWELl

Specifies the dwell time for each list step

:VOLTage[:LEVel]

Specifies the voltage setting for each list step

:LRIPple {<bool>}

Sets low output ripple (noise) mode of operation

:AUTO {<bool>}

Sets automatic changing to the low output ripple (noise) mode of operation

:POWer

:LIMit {<power>}

Sets the output power limit

:PROTection[:LEVel]

Sets the over-power protection (OPP) level

:DELay

[:TIME] {<time>}

Sets the over-power protection programming delay

:STATe {<bool>}

Enables/disables over-power protection on the selected channel

:TRIPped?

Returns status of over-power protection activation

:VOLTage

[:LEVel]

[:IMMediate][:AMPLitude] {<voltage>}

Sets the output voltage

:STEP[:INCRement] {<step>}

Sets the step of the voltage change

:TRIGgered[:AMPLitude] {<voltage>}

Sets the triggered output voltage

:LIMit

[:POSitive][:IMMediate][:AMPLitude] {<voltage>}

Sets the output voltage limit

:MODE {<mode>}

Sets the voltage trigger mode

:PROGram[:SOURce] {<source>}

Sets voltage programming source

:PROTection[:LEVel]

Sets the over-voltage protection (OVP) level

:DELay

[:TIME] {<time>}

Sets the over-voltage protection (OVP) programming delay

:STATe {<bool>}

Enables/disables over-voltage protection on the selected channel

:TRIPped?

Returns status of over-voltage protection activation

:SENSe[:SOURce] {<source>}

Sets voltage sense inputs source

:SLEW

:FALLing

Sets the falling voltage slew rate

:RISing

Sets the rising voltage slew rate

Syntax

[SOURce[<n>]]:CURRent[:LEVel][:IMMediate][:AMPLitude] {<current>}

[SOURce[<n>]]:CURRent[:LEVel][:IMMediate][:AMPLitude]? [<query current>]

Description

This command sets the immediate current level of the channel. Units are in amperes. When [:SOURce[<n>]] or [<n>] is omitted, the currently selected channel will be affected by this command.

This command also increases or decreases the immediate current level using the ‘UP’ or DOWN parameter by a predetermined amount. The command CURRent:STEP sets the amount of increase or decrease. A new increment setting will not cause an execution error -222,"Data out of range" when the maximum or the minimum rated current is exceeded – the output value will be set to the maximum or the minimum value instead.

At *RST, the signal being sourced will be set to a "safe" condition. This is achieved by setting the amplitude to its MINimum value (see Section 8.1).

Return

The query command returns the programmed current level. CURR? MIN, CURR? DEF and CURR? MAX can be used to obtain minimum, default and maximum current level on the currently selected channel. For actual output current value use MEASure:CURRent command.

Parameters

Name

Type

Range

Default

<current>

NR2|Discrete

0 to MAXimum, MIN|DEF|MAX|UP|DOWN

The maximum value is dependent on the PSU current rating. See Section 8.1

–

<query current>

Discrete

MIN|DEF|MAX

–

Usage example

A 10 ohm load is connected and voltage is set to 20 V. With MAX current set measured current will be 2 A. When new current value is set to 1.2 A, voltage will drop to 12 V (the channel enters the CC mode of operation):

INST CH1

VOLT 20

CURR MAX

MEAS:VOLT?

20.00

CURR 1.2

MEAS:VOLT?

12.00

Query that returns maximum current of the currently selected channel:

CURR? MAX

5.00

Errors

150,"Power limit exceeded"

-222,"Data out of range"

Related Commands

*SAV

*RST

APPLy

MEASure[:SCALar]:CURRent[:DC]?

[SOURce[<n>]]:CURRent[:LEVel][:IMMediate]:STEP[:INCRement]

Syntax

[SOURce[<n>]]:CURRent[:LEVel][:IMMediate]:STEP[:INCRement] {<step>}

[SOURce[<n>]]:CURRent[:LEVel][:IMMediate]:STEP[:INCRement]? [<query step>]

Description

Set the step of the current change of the channel. When [SOURce[<n>]] or [<n>] is omitted, the currently selected channel will be affected by this command. Step change is performed by using UP and DOWN as parameter for the [SOURce[<n>]]:CURRent command.

Return

The query returns the step of the current change of the specified channel.

Parameters

Name

Type

Range

Default

<step>

NR2|Discrete

0.01 to 1|DEFault

0.05

<query step>

Discrete

DEFault

–

Usage example

Return default step value:

CURR:STEP? DEF

0.05

When a 10 ohm load is connected with voltage set to 20 V and current to 1 A the first channel enters CC mode of operation. Current is then increased from 1 A in two steps to 1.2 A:

APPL CH1, 20,1

MEAS:VOLT?

10.00

CURR:STEP 0.1

CURR UP

MEAS:CURR?

1.10

CURR UP

MEAS:CURR?

1.20

MEAS:VOLT?

12.00

Related Commands

*SAV

[SOURce[<n>]]:CURRent

Syntax

[SOURce[<n>]]:CURRent[:LEVel]:TRIGgered[:AMPLitude] {<current>}

[SOURce[<n>]]:CURRent[:LEVel]:TRIGgered[:AMPLitude]? [<query current>]

Description

This command programs the pending triggered current level. The pending triggered current level is a stored value that is transferred to the output terminals when a trigger occurs.

A pending triggered level is not affected by subsequent CURRent commands.

Return

Query the triggered current level presently programmed. If no triggered level is programmed, the CURRent level is returned. CURR:TRIG? MIN and CURR:TRIG? MAX return the lowest and highest programmable triggered current levels.

Parameters

Name

Type

Range

Default

<current>

NR2|Discrete

0 to maximum, MIN|DEF|MAX

The MAXimum value is dependent on the PSU current rating. See Section 8.1

0.00

<query current>

Discrete

MIN|DEF|MAX

–

Usage example

On the currently selected channel voltage will be set to 3.3 V and current to 1 A when INITiate command is executed:

VOLT:TRIG 3.3

CURR:TRIG 1

TRIG:SOUR IMM

INIT

Related Commands

ABORt

Syntax

[SOURce[<n>]]:CURRent:LIMit[:POSitive][:IMMediate][:AMPLitude] {<current>}

[SOURce[<n>]]:CURRent:LIMit[:POSitive][:IMMediate][:AMPLitude]? [<query current>]

Description

This command sets the channel’s output current limit. Units are in amperes.

When [:SOURce[<n>]] or [<n>] is omitted, the currently selected channel will be affected by this command.

This command could be used as mean of protection against incidental programming of too high output current that can be set for example with [SOURce[<n>]]:CURRent:STEP command.

Maximum limit value will be affected with detected failure of cooling fan or channel’s temperature sensor. Use CURR:LIM? MAX to query actual value.

Return

The query returns the max. allowed output current of the specified channel. Querying MAX on an output channel returns the maximum current limit.

Parameters

Name

Type

Range

Default

<current>

NR2|Discrete

0 to MAXimum, MIN|DEF|MAX

The MAXimum value is dependent on the PSU current rating. See Section 8.1

MAXimum

<query current>

Discrete

MIN|DEF|MAX

–

Usage example

Normal mode of operation for 5 A model:

CURR:LIM MAX?

5.00

Max. allowable current with faulty cooling fan or temperature sensor:

CURR:LIM MAX?

1.00

Related Commands

*SAV

[SOURce[<n>]]:CURRent:STEP

[SOURce[<n>]]:POWer:LIMit

[SOURce[<n>]]:VOLTage:LIMit[:POSitive][:IMMediate][:AMPLitude]

Syntax

[SOURce[<n>]]:CURRent:MODE {<mode>}

[SOURce[<n>]]:CURRent:MODE?

Description

This command determines what happens to the output current when the transient system is initiated and triggered:

• FIXed – the output current remains at the immediate value
• LIST – the output follows the list values when a trigger occurs.
• STEP – the output goes to the triggered level when a trigger occurs.

Return

The query command returns the current mode of the currently selected channel.

Parameters

Name

Type

Range

Default

<mode>

Discrete

FIXed|LIST|STEP

FIXed

Usage example

CURR:MODE?

FIX

Related Commands

[SOURce[<n>]]:LIST:CURRent[:LEVel]

[SOURce[<n>]]:VOLTage:MODE

Syntax

[SOURce[<n>]]:CURRent:PROTection:DELay[:TIME] {<time>}

[SOURce[<n>]]:CURRent:PROTection:DELay[:TIME]? [<query time>]

Description

This command sets the over-current protection delay. The over-current protection function will not be triggered on the selected output channel during the delay time. After the delay time has expired, the over-current protection function will be active.

This prevents momentary changes in output status from triggering the over-current protection function. Programmed values can range from 0 to 10 seconds. See also Section 8.1

Return

The query command returns the programmed delay time.

Parameters

Name

Type

Range

Default

<time>

NR2|Discrete

0 – 10|DEFault

20 ms

<query time>

Discrete

DEFault

–

Usage example

Get default OCP delay of 20 milliseconds:

CURR:PROT:DEL? DEF

0.02

Related Commands

*SAV

OUTPut:PROTection:CLEar

Syntax

[SOURce[<n>]]:CURRent:PROTection:STATe {<bool>}

[SOURce[<n>]]:CURRent:PROTection:STATe?

Description

This command enables or disables the over-current protection (OCP) function. The enabled state is ON (1); the disabled state is OFF (0).

Since the PSU do not have a dedicated over-current protection circuit that can be programmed independently of output current level, entering the CC (constant current) mode of operation is used as a trigger to start OCP sequence. When delay time specified with the [SOURce[<n>]]:CURRent:PROTection:DELay[:TIME] command expired the output turns off and the Questionable Condition status register OCP bit 9 is set. An error tone will also follow if beeper is enabled (see SYSTem:BEEPer:STATe).

[SOURce[<n>]]:CURRent:PROTection:TRIPped? command can be used to query whether over-current protection occurred on the selected channel.

Return

The query command returns 0 if the current protection state is OFF, and 1 if the current protection state is ON.

Parameters

Name

Type

Range

Default

<bool>

Boolean

ON|OFF|0|1

OFF

Usage example

CURR:PROT:STAT?

0

Related Commands

*SAV

OUTPut:PROTection:CLEar

OUTPut:PROTection:COUPle

[SOURce[<n>]]:CURRent:PROTection:DELay[:TIME]

[SOURce[<n>]]:CURRent:PROTection:TRIPped

SYSTem:BEEPer:STATe

Syntax

[SOURce[<n>]]:CURRent:PROTection:TRIPped?

Description

Query whether OCP occurred on the currently selected channel. When protection is tripped bit 9 (OCP) of the Questionable Instrument Isummary register will be set (see Section 3.4.2).

The OUTPut:PROTection:CLEar command can be send to clear OCP condition on the selected channel.

Return

This query returns a 1 if the protection circuit is tripped and a 0 if it is untripped.

Usage example

CURR:PROT:TRIP?

1

Related Commands

OUTPut:PROTection:CLEar

Syntax

[SOURce[<n>]]:LIST:COUNt {<count>}

[SOURce[<n>]]:LIST:COUNt?

Description

This command sets the number of times that the list is executed before it is completed. The list count range is 1 through 255. Use the INFinity parameter or 0 to execute a list continuously.

Use ABORt to stop the list at any time. When the list is aborted, the output returns to the settings that were in effect before the list started.

Return

The query command returns the list count. Multiple responses are separated by commas. If a repeat count of 0 is returned, it means the list is set to repeat continuously.

Parameters

Name

Type

Range

Default

<count>

NR1|Discrete

0|1 – 65535|INFinity

1

Usage example

LIST:COUN?

10

Related Commands

ABORt

INITiate[:IMMediate]

MMEMory:LOAD:LIST[<n>]

MMEMory:STORe:LIST[<n>]

Syntax

[SOURce[<n>]]:LIST:CURRent[:LEVel] {<current>}[, …]

[SOURce[<n>]]:LIST:CURRent[:LEVel]?

Description

This command specifies the current setting for each list step in amperes. A comma-delimited list of up to 256 steps may be programmed.

The order in which the current values are entered determines the sequence when the list executes.

To create a valid list, the VOLTage, CURRent and DWELl lists must either all be the same length, or have a length of 1, which is interpreted as having the same length as the list with the maximum length.

This command overwrites any previously programmed current list; it does not append to the previous list.

Return

The query command returns the programmed current level. Multiple responses are separated by commas.

Parameters

Name

Type

Range

Default

<current>

NR2|Discrete

0 to maximum, MIN|DEF|MAX|UP|DOWN

The MAXimum value is dependent on the PSU current rating. See Section 8.1

–

Usage example

LIST:CURR 0.25

Errors

306,"Too many list points"

Related Commands

MMEMory:LOAD:LIST[<n>]

MMEMory:STORe:LIST[<n>]

[SOURce[<n>]]:CURRent:MODE

[SOURce[<n>]]:LIST:COUNt

Syntax

[SOURce[<n>]]:LIST:DWELl {<time>}[, …]

[SOURce[<n>]]:LIST:DWELl?

Description

This command specifies the dwell time for each list step. A comma-delimited list of up to 256 steps may be programmed. Dwell time is the time that the output will remain at a specific step. Dwell times can be programmed from 0 through 65535 seconds.

Note that min. dwell time that can be achieved during the list execution depends of MCU activity and waveform shape. Therefore one have to find that out experimentally while list is executed on desired number of channels (one or two). Usage of oscilloscope is recommended for fast transitions since e.g. YT view resolution cannot be set to less then 20 ms. The expected usable min. dwell time goes well below 10 ms (down to 1 ms).

Return

The query command returns the programmed dwell times. Multiple responses are separated by commas.

Parameters

Name

Type

Range

Default

<time>

NR2

0 – 65535

–

Usage example

LIST:DWEL 20ms,10ms,10ms,50ms

Errors

306,"Too many list points"

Related Commands

MMEMory:LOAD:LIST[<n>]

MMEMory:STORe:LIST[<n>]

[SOURce[<n>]]:LIST:COUNt

Syntax

[SOURce[<n>]]:LIST:VOLTage[:LEVel] {<voltage>}[, …]

[SOURce[<n>]]:LIST:VOLTage[:LEVel]?

Description

This command specifies the voltage setting for each list step in volts. A comma-delimited list of up to 256 steps may be programmed.

The order in which the voltage values are entered determines the sequence when the list executes.

To create a valid list, the VOLTage, CURRent and DWELl lists must either all be the same length, or have a length of 1, which is interpreted as having the same length as the list with the maximum length.

This command overwrites any previously programmed voltage list; it does not append to the previous list.

Return

The query command returns the programmed voltage level. Multiple responses are separated by commas.

Parameters

Name

Type

Range

Default

<voltage>

NR2|Discrete

0 to maximum, MIN|DEF|MAX|UP|DOWN

The maximum value is dependent on the PSU voltage rating. See Section 8.1

–

Usage example

Programming the list that contain 4 steps and will be executed 20 times on the channel 2. Execution will start by receiving remote command (*TRG) since BUS is selected as a trigger source:

INST CH2

LIST:COUN 20

LIST:VOLT 0,1.5,3,4.5

LIST:CURR 0.25

LIST:DWEL 20ms,10ms,10ms,50ms

OUTP ON

*OPC?

0

TRIG:SOUR BUS

INIT

*TRG

Errors

306,"Too many list points"

Related Commands

MMEMory:LOAD:LIST[<n>]

MMEMory:STORe:LIST[<n>]

[SOURce[<n>]]:LIST:COUNt

[SOURce[<n>]]:VOLTage:MODE

Syntax

[SOURce[<n>]]:LRIPple {<bool>}

[SOURce[<n>]]:LRIPple?

Description

This command enables or disables low output ripple (noise) mode of operation when it’s supported by installed channel board (use the SYSTem:CHANnel[:INFOrmation]:PROGram? to query channel functionality).

When low ripple mode of operation is selected the power pre-regulator is bypassed by setting so-called Duty cycle of the SMPS controller to 100 %. That will disable switching frequency and therefore that otherwise hard to filter component disappear entirely from the channel output. In that case the remaining noise mainly comes from the low power bias switching pre-regulator.

The maximum output power in this mode of operation is limited to stay within SOA (Safe operating area) of the pre-regulator and post-regulator regulation elements. The maximum output power is limited by the first of the following conditions that is met:

• The pre-regulator regulation element (switching mosfet) capability is limited with max. allowed continuous current (SOA_PREG_CURR value) for the applied input voltage (SOA_VIN value). The set output current cannot exceeds this value in any moment.
• The post-regulator regulation element (pass mosfet) could dissipate finite power (SOA_POSTREG_PTOT value) while load is connected. Therefore output power cannot exceed product of voltage difference (SOA_VIN and output voltage) and output current.

For example, when output voltage is set to 12 V and SOA_VIN = 50 V, SOA_PREG_CURR = 0.8 A and SOA_POSTREG_PTOT = 20 W, the max. output current in low ripple mode cannot exceed 0.526 A because SOA_VIN-VOLT = 50-12 = 38 V and Imax=SOA_POSTREG_PTOT/38 = 20/38 = 0.526 A.

If output voltage is set to 36 V with the same SOA values as in example above the max. output current cannot exceed 0.8 A (limited by SOA_PREG_CURR) regardless of the fact that max. power dissipation of 20 W allows output current of up to 1.428 A or 20/(50-36).

If low ripple mode is set an error will be generated when any of the limits are exceeded. The AUTOmatic mode should be used to avoid error conditions. Also if AUTOmatic mode disables low ripple, an attempt to enable it using the [SOURce[<n>]]:LRIPple ON command will generate an execution error.

An attempt to enter low ripple mode while remote (EXTernal) voltage programming is active ([SOURce[<n>]]:VOLTage:PROGram[:SOURce]) will generate -221 error.

Parameters

Name

Type

Range

Default

<bool>

Boolean

ON|OFF|0|1

OFF

Return

The query command returns 1 if the low ripple mode is active, and 0 if the low ripple mode is not active.

Usage example

VOLT:LRIP?

0

Errors

-200,"Execution error"

-221,"Settings conflict"

-241,"Hardware missing"

Related Commands

*SAV

[SOURce[<n>]]:LRIPple:AUTO

SYSTem:CHANnel:INFOrmation:PROGram?

Syntax

[SOURce[<n>]]:LRIPple:AUTO {<bool>}

[SOURce[<n>]]:LRIPple:AUTO?

Description

Use this command to allow automatic changing to the low ripple (noise) mode of operation.

If AUTOmatic mode of operation is enabled, the channel will stay in low ripple mode of operation as long as output power does not exceed calculated limitations allowed for that mode of operation. The [SOURce[<n>]]:LRIPple? query can be used to determine current status.

Parameters

Name

Type

Range

Default

<bool>

Boolean

ON|OFF|0|1

OFF

Return

The query command returns 1 if the low ripple automatic mode is active, and 0 if the low ripple automatic mode is not active.

Usage example

VOLT:LRIP:AUTO 1

VOLT:LRIP?

1

Errors

-241,"Hardware missing"

312,"Cannot execute when the channels are coupled"

Related Commands

*SAV

INSTrument:COUPle:TRACking

SOURce[<n>]]:LRIPple

SYSTem:CHANnel:INFOrmation:PROGram?

Syntax

[SOURce[<n>]]:POWer:LIMit {<power>}

[SOURce[<n>]]:POWer:LIMit? [<query power>]

Description

This command sets the channel’s output power limit. Units are in Watts. Such limitation is required if main transformer (or AC/DC adapter if DC power input is used) cannot provide the same power as connected channel power module. For example if power module can deliver 200 W but main transformer offer only 160 W then MAXimum allowable continuous power is only 160 W.

Return

The query returns the max. allowed output power of the specified channel. Querying MAX on an output channel returns the maximum rated power limit.

Parameters

Name

Type

Range

Default

<power>

NR2|Discrete

0 to MAXimum, MIN|DEF|MAX

The MAXimum value is dependent on the PSU power rating. See Section 8.1

MAXimum

<query power>

Discrete

MIN|MAX

–

Usage example

POW:LIM DEF

POW:LIM?

150.00

Related Commands

*SAV

[SOURce[<n>]]:CURRent:LIMit[:POSitive][:IMMediate][:AMPLitude]

[SOURce[<n>]]:VOLTage:LIMit[:POSitive][:IMMediate][:AMPLitude]

Syntax

[SOURce[<n>]]:POWer:PROTection[:LEVel] {<power>}

[SOURce[<n>]]:POWer:PROTection[:LEVel]?

Description

Set the over-power protection (OPP) value of the channel. When [:SOURce[<n>]] or [<n>] is omitted, the currently selected channel will be affected by this command. When the over-power protection function of the specified channel is enabled ([SOURce[<n>]]:POWer:PROTection:STATe), the output turns off automatically when the output power exceeds the over-power protection value currently set.

[SOURce[<n>]]:POWer:PROTection:TRIPped? command can be used to query whether over-power protection occurred on the selected channel.

Return

Query the over-power protection (OPP) value of the selected channel.

Parameters

Name

Type

Range

Default

<power>

NR2|Discrete

0 to MAXimum, MIN|DEF|MAX

The maximum value is dependent on the PSU power rating. See Section 8.1

DEFault

Usage example

Set power protection to 50 W on the channel 2:

SOUR2:POW:PROT 50

Related Commands

*SAV

OUTPut:PROTection:COUPle

[SOURce[<n>]]:POWer:PROTection:TRIPped?

[SOURce[<n>]]:POWer:PROTection:STATe

Syntax

[SOURce[<n>]]:POWer:PROTection:DELay[:TIME] {<time>}

[SOURce[<n>]]:POWer:PROTection:DELay[:TIME]? [<query time>]

Description

This command sets the over-power protection (OPP) delay. The over-power protection function will not be triggered on the selected output channel during the delay time. After the delay time has expired, the over-power protection function will be active.

This prevents momentary changes in output status from triggering the over-power protection function. Programmed values can range from 0 to 300 seconds. See also Section 8.1

Return

The query command returns the programmed delay time.

Parameters

Name

Type

Range

Default

<time>

NR2|Discrete

0 – 300|DEFault

10

<query time>

Discrete

DEFault

–

Usage example

Get default OPP delay of 10 seconds:

POW:PROT:DEL? DEF

10

Related Commands

*SAV

OUTPut:PROTection:CLEar

Syntax

[SOURce[<n>]]:POWer:PROTection:STATe {<bool>}

[SOURce[<n>]]:POWer:PROTection:STATe?

Description

This command enables or disables the over-power protection (OPP) function. The enabled state is ON (1); the disabled state is OFF (0). If the over-power protection function is enabled and the measure output power reach value set by [SOURce[<n>]]:POWer:PROTection[:LEVel] the output is disabled and the Questionable Condition status register OPP bit 10 is set.

Return

The query command returns 0 if the current protection state is OFF, and 1 if the current protection state is ON.

Parameters

Name

Type

Range

Default

<bool>

Boolean

ON|OFF|0|1

OFF

Usage example

POW:PROT:STAT ON

POW:PROT:STAT?

1

Related Commands

*SAV

OUTPut:PROTection:CLEar

[SOURce[<n>]]:POWer:PROTection[:LEVel]

Syntax

[SOURce[<n>]]:POWer:PROTection:TRIPped?

Description

Query whether OPP occurred on the currently selected channel. When protection is tripped bit 10 (OPP) of the Questionable Instrument Isummary register will be set (see Section 3.4.2).

The OUTPut:PROTection:CLEar command can be send to clear OPP condition on the selected channel.

Return

This query returns a 1 if the protection circuit is tripped and a 0 if it is untripped.

Usage example

POW:PROT:TRIP?

0

Related Commands

OUTPut:PROTection:CLEar

Syntax

[SOURce[<n>]]:VOLTage[:LEVel][:IMMediate][:AMPLitude] {<voltage>}

[SOURce[<n>]]:VOLTage[:LEVel][:IMMediate][:AMPLitude]? [<query voltage>]

Description

This command sets the immediate voltage level of the output channel. Units are in volts. When [:SOURce[<n>]] or [<n>] is omitted, the currently selected channel will be affected by this command.

This command also increases or decreases the immediate voltage level using the ‘UP’ or DOWN parameter by a predetermined amount. The command VOLTage:STEP sets the amount of increase or decrease. A new increment setting will not cause an execution error -222,"Data out of range" when the maximum or the minimum rated current is exceeded – the output value will be set to the maximum or the minimum value instead.

At *RST, the signal being sourced will be set to a "safe" condition. This is achieved by setting the amplitude to its MINimum value (see Section 8.1).

Return

The query command returns the programmed voltage level. VOLT? MIN, VOLT? DEF and VOLT? MAX can be used to obtain minimum, default and maximum voltage level on the currently selected channel. For actual output voltage value use MEASure:VOLTage? command.

Parameters

Name

Type

Range

Default

<voltage>

NR2|Discrete

0 to MAXimum, MIN|DEF|MAX|UP|DOWN

The maximum value is dependent on the PSU voltage rating. See Section 8.1

–

<query voltage>

Discrete

MIN|DEF|MAX

–

Usage example

A 10 ohm load is connected and current is set to 1 A. With MAX voltage set measured voltage will be 10 V. When new voltage value is set to 5 V, current will drop to 0.5 A (the channel enters the CV mode of operation):

INST CH1

VOLT MAX

CURR 1

MEAS:CURR?

1.00

VOLT 5

MEAS:CURR?

0.50

Query that returns maximum current of the currently selected channel:

CURR? MAX

5.00

Errors

150,"Power limit exceeded"

-222,"Data out of range"

Related Commands

*SAV

*RST

APPLy

MEASure[:SCALar]:VOLTage[:DC]?

[SOURce[<n>]]:VOLTage[:LEVel][:IMMediate]:STEP[:INCRement]

Syntax

[SOURce[<n>]]:VOLTage:LIMit[:POSitive][:IMMediate][:AMPLitude] {<voltage>}

[SOURce[<n>]]:VOLTage:LIMit[:POSitive][:IMMediate][:AMPLitude]? [<query voltage>]

Description

This command sets the channel’s output voltage limit. Units are in volts.

When [:SOURce[<n>]] or [<n>] is omitted, the currently selected channel will be affected by this command.

This command could be used as mean of protection against incidental programming of too high output voltage that can be set for example with [SOURce[<n>]]:VOLTage:STEP command.

Return

The query returns the max. allowed output voltage of the specified channel. Querying MAX on an output channel returns the maximum voltage limit.

Parameters

Name

Type

Range

Default

<voltage>

NR2|Discrete

0 to MAXimum, MIN|DEF|MAX

The MAXimum value is dependent on the PSU current rating. See Section 8.1

MAXimum

<query voltage>

Discrete

MIN|MAX

–

Usage example

VOLT:LIM 20

Related Commands

*SAV

[SOURce[<n>]]:CURRent:STEP

[SOURce[<n>]]:POWer:LIMit

[SOURce[<n>]]:VOLTage:LIMit[:POSitive][:IMMediate][:AMPLitude]

Syntax

[SOURce[<n>]]:VOLTage[:LEVel][:IMMediate]:STEP[:INCRement] {<step>}

[SOURce[<n>]]:VOLTage[:LEVel][:IMMediate]:STEP[:INCRement]? [<query step>]

Description

Set the step of the voltage change of the channel. When [SOURce[<n>]] or [<n>] is omitted, the currently selected channel will be affected by this command. Step change is performed by using UP and DOWN as parameter for the [SOURce[<n>]]:VOLTage command.

Return

The query returns the step of the voltage change of the specified channel.

Parameters

Name

Type

Range

Default

<step>

NR2|Discrete

0.01 to 10|DEFault

0.1

<query step>

Discrete

DEFault

–

Usage example

Return default step value:

VOLT:STEP? DEF

0.10

By connecting a 10 ohm load and current set to 2 A and voltage to 10 V the first channel enters the CV mode of operation. Voltage is then decreased from 10 V in two steps to 6 V:

APPL CH1, 10,2

MEAS:CURR?

1.0

VOLT:STEP 2

VOLT DOWN

VOLT DOWN

MEAS:VOLT?

6.0

MEAS:CURR?

0.60

Related Commands

*SAV

[SOURce[<n>]]:VOLTage

Syntax

[SOURce[<n>]]:VOLTage[:LEVel]:TRIGgered[:AMPLitude] {<voltage>}

[SOURce[<n>]]:VOLTage[:LEVel]:TRIGgered[:AMPLitude]? [<query voltage>]

Description

This command programs the pending triggered voltage level. The pending triggered current level is a stored value that is transferred to the output terminals when a trigger occurs.

A pending triggered level is not affected by subsequent VOLTage commands.

Return

Query the triggered voltage level presently programmed. If no triggered level is programmed, the VOLTage level is returned. VOLT:TRIG? MIN and VOLT:TRIG? MIN return the lowest and highest programmable triggered voltage levels.

Parameters

Name

Type

Range

Default

<voltage>

NR2|Discrete

0 to maximum, MIN|DEF|MAX

The maximum value is dependent on the PSU voltage rating. See Section 8.1

0.00

<query voltage>

Discrete

MIN|MAX

Usage example

On the currently selected channel voltage will be set to 3.3V and current to 1A when INITiate command is executed:

VOLT:TRIG 3.3

CURR:TRIG 1

TRIG:SOUR IMM

INIT

Related Commands

ABORt

Syntax

[SOURce[<n>]]:VOLTage:MODE {<mode>}

[SOURce[<n>]]:VOLTage:MODE?

Description

This command determines what happens to the output voltage when the transient system is initiated and triggered:

• FIXed – the output current remains at the immediate value
• LIST – the output follows the list values when a trigger occurs.
• STEP – the output goes to the triggered level when a trigger occurs.

Return

The query command returns the voltage mode of the currently selected channel.

Parameters

Name

Type

Range

Default

<mode>

Discrete

FIXed|LIST|STEP

FIXed

Usage example

VOLT:MODE?

LIST

Related Commands

[SOURce[<n>]]:LIST:VOLTage[:LEVel]

[SOURce[<n>]]:CURRent:MODE

Syntax

[SOURce[<n>]]:VOLTage:PROGram[:SOURce] {<source>}

[SOURce[<n>]]:VOLTage:PROGram[:SOURce]?

Description

Use this command to define source for output voltage programming if channel support this option (use the SYSTem:CHANnel[:INFOrmation]:PROGram? to query channel programming capability).

A channel’s D/A converter controlled by CPU is used by default for voltage output programming. That source can be calibrated (see the CALibrate subsystem) and provide output within safe limits.

The external voltage programming could be used when fast interaction with an external process is required. For example if tracking output of the connected D.U.T. (i.e. a power supply) is needed the PSU effectively becomes a pre-regulator keeping its output voltage in relation with changes of the D.U.T. output keeping constant difference between connected D.U.T input and output and in that way its max. power dissipation.

Max. D/A converter programmed voltage of 2.5 V would results with MAXimal voltage output regardless of the channel’s voltage range (see Section 8.1). Therefore if EXTernal programming source is selected, any voltage value higher then 2.5 V could produce unexpected results and eventually damage the PSU and/or connected load.

To limit possible damage when programming source is set to EXTernal, the over-voltage protection (OVP) will be activated and set to MAXimum ([SOURce[<n>]]:VOLTage:PROTection[:LEVel]) with protection delay time set to zero ([SOURce[<n>]]:VOLTage:PROTection:DELay[:TIME]). Further adjustment of OVP level and delay is also allowed (e.g. to decrease OVP level or increase delay time).

The enabled state is EXTernal (1); the disabled state is INTernal (0). Execution of this command also affects bit 13 (RPROG) of the Operation Instrument Isummary register (see Section 3.3.2).

Self-test operation initiated by *TST? command will reset voltage programming on all PSU channels to the internal/local source.

If external programming source is selected the DIAGnostic[:INFOrmation]:ADC? Query returns 0.00 value for U_SET.

Parameters

Name

Type

Range

Default

<source>

Discrete

INTernal|EXTernal

INTernal

Return

The query command returns 0 if the local (internal) voltage programming is selected, and 1 if the remote (external) sense is selected.

Usage example

VOLT:PROG EXT

VOLT:PROG?

1

Errors

-241,"Hardware missing"

312,"Cannot execute when the channels are coupled"

Related Commands

*TST

DIAGnostic[:INFOrmation]:ADC?

INSTrument:COUPle:TRACking

OUTPut:[:STATe]

[SOURce[<n>]]:VOLTage:PROTection[:LEVel]

[SOURce[<n>]]:VOLTage:PROTection:DELay[:TIME]

[SOURce[<n>]]:VOLTage:PROTection:TRIPped?

SYSTem:CHANnel[:INFOrmation:PROGram?

Syntax

[SOURce[<n>]]:VOLTage:PROTection[:LEVel] {<voltage>}

[SOURce[<n>]]:VOLTage:PROTection[:LEVel]?

Description

Set the over-voltage protection (OVP) value of the channel. When [:SOURce[<n>]] or [<n>] is omitted, the currently selected channel will be affected by this command. When the over-votlage protection function of the specified channel is enabled ([SOURce[<n>]]:VOLTage:PROTection:STATe), the output turns off automatically when the output voltage exceeds the over-voltage protection value currently set.

[SOURce[<n>]]:VOLTage:PROTection:TRIPped? command can be used to query whether over-voltage protection occurred on the selected channel.

An execution error -222,"Data out of range" will be generated when output voltage is controlled internally ([SOURce[<n>]]:VOLTage:PROGram[:SOURce]) and OVP value is set below programmed output voltage ([SOURce[<n>]]:VOLTage).

Return

Query the over-voltage protection (OVP) value of the selected channel.

Parameters

Name

Type

Range

Default

<voltage>

NR2|Discrete

0 to maximum, MIN|DEF|MAX

The maximum value is dependent on the PSU voltage rating. See Section 8.1

–

Usage example

Set voltage protection to 10.2 V on the channel 1:

SOUR1:VOLT:PROT 10.2

Errors

-222,"Data out of range"

Related Commands

*SAV

OUTPut:PROTection:COUPle

[SOURce[<n>]]:VOLTage

[SOURce[<n>]]:VOLTage:PROGram[:SOURce]

[SOURce[<n>]]:VOLTage:PROTection:TRIPped?

[SOURce[<n>]]:VOLTage:PROTection:STATe

Syntax

[SOURce[<n>]]:VOLTage:PROTection:DELay[:TIME] {<time>}

[SOURce[<n>]]:VOLTage:PROTection:DELay[:TIME]? [<query time>]

Description

This command sets the over-voltage protection delay. The over-voltage protection function will not be triggered on the selected output channel during the delay time. After the delay time has expired, the over-voltage protection function will be active.

This prevents momentary changes in output status from triggering the over-voltage protection function. Programmed values can range from 0 to 10 seconds. See also Section 8.1

Return

The query command returns the programmed delay time.

Parameters

Name

Type

Range

Default

<time>

NR2|Discrete

0 – 10|DEFault

5 ms

<query time>

Discrete

DEFault

–

Usage example

Get default OVP delay of 50 milliseconds:

VOLT:PROT:DEL? DEF

0.050

Related Commands

*SAV

OUTPut:PROTection:CLEar

Syntax

[SOURce[<n>]]:VOLTage:PROTection:STATe {<bool>}

[SOURce[<n>]]:VOLTage:PROTection:STATe?

Description

This command enables or disables the over-voltage protection (OVP) function. The enabled state is ON (1); the disabled state is OFF (0).

Since the PSU do not have a dedicated over-voltage protection circuit that can be programmed independently of output current level, entering the CV (constant voltage) mode of operation is used as a trigger to start OVP sequence. When delay time specified with the [SOURce[<n>]]:VOLTage:PROTection:DELay[:TIME] command expired the output turns off and the Questionable Condition status register OCP bit 8 is set. An error tone will also follow if beeper is enabled (see SYSTem:BEEPer:STATe).

[SOURce[<n>]]:VOLTage:PROTection:TRIPped? command can be used to query whether over-voltage protection occurred on the selected channel.

Return

The query command returns 0 if the voltage protection state is OFF, and 1 if the voltage protection state is ON.

Parameters

Name

Type

Range

Default

<bool>

Boolean

ON|OFF|0|1

OFF

Usage example

VOLT:PROT:STAT?

0

Related Commands

*SAV

OUTPut:PROTection:CLEar

[SOURce[<n>]]:VOLTage:PROTection:DELay[:TIME]

[SOURce[<n>]]:VOLTage:PROTection:TRIPped

SYSTem:BEEPer:STATe

Syntax

[SOURce[<n>]]:VOLTage:PROTection:TRIPped?

Description

Query whether OVP occurred on the currently selected channel. When protection is tripped bit 8 (OVP) of the Questionable Instrument Isummary register will be set (see Section 3.4.2).

When channel’s output voltage is controlled remotely ([SOURce[<n>]]:VOLTage:PROGram[:SOURce]) this protection will change voltage control back to INTernal source.

The OUTPut:PROTection:CLEar command can be send to clear OVP condition on the selected channel.

Return

This query returns a 1 if the protection circuit is tripped and a 0 if it is untripped.

Usage example

VOLT:PROT:TRIP?

0

VOLT:PROG?

0

Related Commands

OUTPut:PROTection:CLEar

[SOURce[<n>]]:VOLTage:PROGram[:SOURce]

Syntax

[SOURce[<n>]]:VOLTage:SENSe[:SOURce] {<source>}

[SOURce[<n>]]:VOLTage:SENSe[:SOURce]?

Description

This command enables or disables remote sensing. The enabled state is EXTernal (1); the disabled state is INTernal (0). Execution of this command also affects bit 12 (RSENSE) of the Operation Instrument Isummary register (see Section 3.3.2).

Self-test operation initiated by *TST? command will put remote sense on all PSU channels into disable state.

When the BP_OPTION is enabled and the channels are not coupled together (INSTrument:COUPle:TRACking) this command sets LED indicators above binding posts and sense relays in the following manner:

• Turn on/off Sense1 indicator (LED_S1) and sense relay K_S1 when CH1 is selected
• Turn on/off Sense2 indicators (LED_S2) and sense relay K_S2 when CH2 is selected

Remote sensing has no effect during CC (Constant Current) operation. Sense+/Sense- indicators (LED_S1, LED_S2) will not be affected if output state is off (OUTPut OFF command).

Parameters

Name

Type

Range

Default

<source>

Discrete

INTernal|EXTernal

INTernal

Return

The query command returns 0 if the internal sense is selected, and 1 if the remote (external) sense is selected.

Usage example

VOLT:SENS EXT

VOLT:SENS?

1

Errors

-241,"Hardware missing"

312,"Cannot execute when the channels are coupled"

Related Commands

*SAV

*TST

INSTrument:COUPle:TRACking

OUTPut:[:STATe]

SYSTem:CHANnel[:INFOrmation]:PROGram?