5.2. CALibration

This subsystem provides commands for the PSU calibration. Only one channel can be calibrated at a time. If calibration mode has not been enabled with CALibration:STATe, the calibration commands will generate an error. Use CALibration:SAVE to save any changes, otherwise all changes will be lost on exit from calibration mode. Within the same calibration session both output voltage and current can be calibrated for the currently selected channel.

Calibration cannot start if channel output is not enabled (OUTPut[:STATe] ON). During calibration process three points has to be entered: MIN, MID and MAX. But in practice two point calibration is performed to re-scale the output programmed and measured values by correcting both slope and offset errors. MID point is used only as an additional validation that between entered MIN and MAX values it’s possible to “draw” a line within allowed minor tolerance.

 

SCPI Command

Description

CALibration[:MODE] {<bool>, <password>}

Enables/disables calibration mode

:CLEar {<password>}

Clears all calibration parameters

:CURRent

 

[:DATA] {<new value>}

Enters the calibration value

:LEVel {<level>}

Calibrates the output current programming

:RANGe {range}

Sets current range for multiple current range model

:PASSword

 

:NEW {<old>, <new>}

Changes calibration password

:REMark {<string>}

Saves calibration information

:SAVE

Saves the new cal constants in non-volatile memory

:SCReen:INIT

Initiates touchscreen calibration procedure

:STATe {<bool>, <password>}

Enables calibration parameters

:VOLTage

 

[:DATA] {<new value>}

Enters the calibration value

:LEVel {<level>}

Calibrates the output voltage programming

5.2.1. CALibration[:MODE]

Syntax

CALibration[:MODE] {<bool> <password>}

CALibration[:MODE]?

Description

This command enables or disables calibration mode. Calibration mode must be enabled for the channel to accept any calibration commands. The first parameter specifies the ON (1) or OFF (0) state. The second parameter is the password. Successful execution of this command set both output VOLTage and CURRent of the selected channel to the MINimum value (see Section 8.1).

Execution of this command also affects bit 0 (CALibrating) of the Operation Instrument Isummary register (see Section 3.3.2).

 

If both voltage and current calibration parameters exists on calibration mode exit (CALibration[:MODE] OFF) the CALibration:STATe ON command will automatically follows.

Parameters

Name

Type

Range

Default

<bool>

Discrete

ON|OFF|0|1

OFF

 

<password>

Quoted string

4 to 16 characters

"eezpsu"

Return

The returned parameter is 0 (OFF) or 1 (ON).

Usage example

See Section 10.2

Errors

102,"Invalid cal password"

104,"Bad sequence of calibration commands"

312,"Cannot execute when the channels are coupled"

Related Commands

CALibration:STATe

DIAGnostic[:INFOrmation]:OTIMe?

INSTrument:COUPle:TRACking

5.2.2. CALibration:CLEar

Syntax

CALibration:CLEar {<password>}

Description

Clear all calibration parameters stored in the non-volatile memory for the currently selected channel. After successful execution of this command CALibration:STATe will be set to OFF (0) and further usage of the calibration data will be disabled. This command will be also filled calibration remark with the date and note that calibration data has been cleared.

Parameters

Name

Type

Range

Default

<password>

Quoted string

4 to 16 characters

"eezpsu"

Return

None

Usage example

DIAG:CAL?

"remark=20170331 new cal","u_cal_params_exists=1","u_min_level=0.150V","u_min_data=0.1
06V","u_min_adc=0.165V","u_mid_level=19.100V","u_mid_data=19.056V
","u_mid_adc=18.500V","u_max_level=38.000V","u_max_data=37.956V",
"u_max_adc=36.791V","u_min_range=0.000V","u_max_range=40.000V","i
_5A_cal_params_exists=1","i_5A_min_level=0.050A","i_5A_min_data=0
.057A","i_5A_min_adc=0.050A","i_5A_mid_level=2.425A","i_5A_mid_da
ta=2.438A","i_5A_mid_adc=2.368A","i_5A_max_level=4.800A","i_5A_ma
x_data=4.811A","i_5A_max_adc=4.686A","i_5A_min_range=0.000A","i_5
A_max_range=5.000A","i_500mA_cal_params_exists=1","i_500mA_min_le
vel=0.0050A","i_500mA_min_data=0.0060A","i_500mA_min_adc=0.0051A"
,"i_500mA_mid_level=0.2425A","i_500mA_mid_data=0.2617A","i_500mA_
mid_adc=0.2368A","i_500mA_max_level=0.4800A","i_500mA_max_data=0.
5170A","i_500mA_max_adc=0.4686A","i_500mA_min_range=0.0000A","i_5
00mA_max_range=0.0000A"

CAL:STAT?

1

CAL:CLE “eezpsu”

CAL:STAT?

0

DIAG:CAL?

"remark= Not calibrated","u_cal_params_exists=0","i_cal_params_exists=0"

Errors

102,"Invalid cal password"

Related Commands

CALibration:STATe

DIAGnostic[:INFOrmation]:CALibration?

5.2.3. CALibration:CURRent[:DATA]

Syntax

CALibration:CURRent[:DATA] {<new value>}

Description

This command can only be used when calibration is enabled and the output state of the currently selected channel is ON. It enters a current value that is obtained by reading an external meter. The minimum calibration level (CAL:CURR:LEV MIN) has to be selected first for the value being entered, then the middle and maximum calibration levels (CAL:CURR:LEV MID and CAL:CURR:LEV MAX) for the value being entered. Three successive values must be selected and entered. Data values are expressed in base units – either volts or amperes, depending on which function is being calibrated.

Parameters

Name

Type

Range

Default

<new value>

numeric (NR2)

-0.2A to MAX + 0.2A

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

Return

None

Usage example

See Section 10.2

Errors

104,"Bad sequence of calibration commands"

107,"Cal value out of range"

5.2.4. CALibration:CURRent:LEVel

Syntax

CALibration:CURRent:LEVel {<level>}

Description

This command can only be used when calibration is enabled and the output state of the currently selected channel is ON. It sets the PSU to a calibration point that is entered with the CAL:CURR command. During calibration, three points must be entered and the low-end point (MIN) must be selected and entered first.

 

This command will set output voltage to MAXimum / 2 (for example 25V for the PSU model with 0-50V).

 

When calibration LEVel is set it’s possible to override its default value using the CURRent command. That could be especially useful when LOW range is calibrating with average 3½-digit multimeter with full scale of 200 mA that is not enough to measure MID and MAX level. Therefore instead of predefined 242.5 mA and 480 mA one can set e.g. 100 mA and 200 mA to stay within multimeter’s low current range (next one is usually 10 A or 20 A that cannot be used to get satisfactory results).

Parameters

Name

Type

Range

Default

<level>

Discrete

MIN|MID|MAX (see also Section 8.1)

Return

None

Usage example

See Section 10.2

Errors

101,"Calibration state is off"

104,"Bad sequence of calibration commands"

Related Commands

CALibration:STATe

INSTrument:NSELect

INSTrument[:SELect]

[SOURce[<n>]]:CURRent

5.2.5. CALibration:CURRent:RANGe

Syntax

CALibration:CURRent:RANGe {<range>}

Description

When PSU is equipped with Power boards that has multiple current range (e.g. r5B12 that can be find out with the SYSTem:CHANnel:MODel? command) it’s recommended to perform calibration of both range. Use this command to select current range on which calibration will be accomplished.

Parameters

Name

Type

Range

Default

<range>

Discrete

HIGH|LOW|5|0.5

HIGH|5

Return

None

Usage example

See Section 10.2

Errors

101,"Calibration state is off"

-241,"Hardware missing"

Related Commands

CALibration:CURRent:LEVel

CALibration:STATe

SYSTem:CHANnel:MODel?

5.2.6. CALibration:PASSword:NEW

Syntax

CALibration:PASSword:NEW {<old>, <new>}

Description

Enter a new calibration password. To change the password, first unsecure the PSU using the old password. Then, the new code has to be entered. The calibration code may contain up to 16 characters over the remote interface. Minimum length is 4 characters.

The new password is automatically stored in non-volatile memory and does not have to be stored with CALibration:SAVE.

Parameters

Name

Type

Range

Default

<old>

Quoted string

4 to 16 characters

eezpsu

 

<new>

Quoted string

4 to 16 characters

Return

None

Usage example

CAL:PASS:NEW "eezpsu", "mycal1234"

Errors

102,"Invalid cal password"

105,"Cal password too long"

106,"Cal password too short"

5.2.7. CALibration:REMark

Syntax

CALibration:REMark {<user remark>}

CALibration:REMark?

Description

Record calibration information about the PSU. The calibration message is consist of two parts:

  • datetime stamp in format yyyymmdd and
  • up to 32 characters.

The PSU should be in calibration mode before sending a calibration message.

Parameters

Name

Type

Range

Default

<user remark>

Quoted string

0 to 32 characters

"Calibration passed"

Return

Query the calibration message.

Usage example

When CAL:REM with text "Calibrated by EEZ" is executed at 2015-09-14:

CAL:REM "Calibrated by EEZ"

CAL:REM?

"20150904 Calibrated by EEZ"

See also Section 10.2

Errors

The following errors could be generated by command but not query:

101,"Calibration state is off"

104,"Bad sequence of calibration commands"

Related Commands

CALibration:STATe

5.2.8. CALibration:SAVE

Syntax

CALibration:SAVE

Description

This command saves calibration constants in non-volatile memory after the calibration procedure has been completed. If calibration mode is exited by programming CALibration:STATe OFF without first saving the new constants, the previous constants are restored. Execution of this command also affects bit 0 (CALibrating) of the Operation Instrument Isummary register (see Section 3.3.2).

Return

None

Usage example

See Section 10.2

Errors

-340,"Calibration failed"

101,"Calibration state is off"

104,"Bad sequence of calibration commands"

111,"No new cal data exists"

5.2.9. CALibration:SCReen:INIT

Syntax

CALibration:SCReen:INIT

Description

Use this command to initiate calibration procedure when touchscreen calibration data are lost or corrupted. Calibration has to be performed locally on the PSU.

 

New calibration procedure can be initiated also by touching the screen and hold for more then 30 seconds.

Return

None

Usage example

CAL:SCR:INIT

5.2.10. CALibration:STATe

Syntax

CALibration:STATe {<bool>}

CALibration:STATe?

Description

This command enables or disables usage of calibration parameters if they exists.

Parameters

Name

Type

Range

Default

<bool>

Discrete

OFF|ON|0|1

ON

Return

The returned parameter is 0 (OFF) or 1 (ON).

Usage example

CAL:STAT OFF

Errors

110,"Cal params missing or corrupted"

Related Commands

DIAGnostic[:INFOrmation]:OTIMe?

5.2.11. CALibration:VOLTage[:DATA]

Syntax

CALibration:VOLTage[:DATA] {<new value>}

Description

This command can only be used when calibration is enabled and the output state of the currently selected channel is ON. It enters a voltage value that you obtained by reading an external meter. You must first select the minimum calibration level (CAL:VOLT:LEV MIN) for the value being entered. You must then select the middle and maximum calibration levels (CAL:VOLT:LEV MID and CAL:VOLT:LEV MAX) for the value being entered. Three successive values must be selected and entered. The PSU then computes new voltage calibration constants. These constants has to be stored in non-volatile memory with CALibration:SAVE command.

Parameters

Name

Type

Range

Default

<new value>

numeric (NR2)

-0.5V to MAX + 0.5V

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

Return

None

Usage example

See Section Section 10.2

Errors

104,"Bad sequence of calibration commands"

107,"Cal value out of range"

Related Commands

CALibration:SAVE

CALibration:STATe

INSTrument:NSELect

INSTrument[:SELect]

5.2.12. CALibration:VOLTage:LEVel

Syntax

CALibration:VOLTage:LEVel {<level>}

Description

This command can only be used when calibration is enabled and the output state of the currently selected channel is ON. It sets the PSU to a calibration point that is entered with the CAL:VOLT[:DATA] command. During calibration, three points must be entered and the low-end point (MIN) must be selected and entered first.

 

This command will set output current to 50mA.

 

When calibration LEVel is set it’s possible to override its default value using the VOLTage command.

Parameters

Name

Type

Range

Default

<level>

Discrete

MIN|MID|MAX (see also Section 8.1)

Return

None

Usage example

See Section Section 10.2

Errors

101,"Calibration state is off"

104,"Bad sequence of calibration commands"

Related Commands

CALibration:STATe

INSTrument:NSELect

INSTrument[:SELect]

[SOURce[<n>]]:VOLTage