9. SCPI Command Set

Standard Commands for Programmable Instrumentation (SCPI) support is provided for all MagnaLOAD electronic load products. These commands provide programming compatibility with other instruments. SCPI commands are ASCII textual strings, which are sent to the instrument over the physical layer, providing support over all communication interfaces. Utilizing these SCPI commands provides the simplest form of programming a MagnaLOAD electronic load product, as they are driver and programming environment independent. Further information about the SCPI standard and conventions are in the section: SCPI Introduction. The full list of linked commands are in section: SCPI Command Reference List.

9.1. SCPI Introduction

9.1.1. Command Structure

There are two types of SCPI messages: program and response.

A program message consists of one or more properly formatted SCPI commands sent from the controller to the MagnaLOAD electronic load. The message, which may be sent at any time, requests the MagnaLOAD electronic load to perform some action.

A response message consists of data in a specific SCPI format sent from the MagnaLOAD electronic load to the controller. The MagnaLOAD electronic load sends the message only when requested from a program message query.

9.1.2. Data Types

The following datatypes, referenced in the SCPI command descriptions, describe the responses from query SCPI commands:

<NR1>
Digits with an implied decimal point assumed at the right of the least-significant digit. Example: 273
<NR2>
Digits with an explicit decimal point. Example: .0273
<NR3>
Digits with an explicit decimal point and an exponent. Example: 2.73E+2

The following data types, referenced in the SCPI command descriptions, describe the parameters from program SCPI commands:

<Nrf>
Extended format that includes <NR1>, <NR2>, and <NR3>. Examples: 273, 273., 2.73E2
<Nrf+>
Expanded decimal format that includes <NRf> and MIN MAX. MIN and MAX are the minimum and maximum limit values that are implicit in the range specification for the parameter. Examples: 273, 273., 2.73E2, MAX
<Bool>
Boolean Data. Example: 0 | 1 or ON | OFF

9.1.3. Termination

A new line <NL> character must be sent to the MagnaLOAD electronic load to terminate a SCPI command string. The IEEE-488 EOI (End-Or-Identify) message is interpreted as a <NL> character and can be used to terminate a command string in place of an <NL>. A carriage return followed by a new line <CR><NL> is also accepted. Command string termination will always reset the current SCPI command path to the root level.

9.1.4. Syntax Conventions

Square brackets []
Used to enclose a parameter that is optional when programming the command; that is, the instrument shall process the command to have the same effect whether the option node is omitted by the programmer or not.
Angle brackets <>
Used to enclose mandatory parameters or to indicate a returned parameter. For example, in the CURRent <value> command syntax, the <value> parameter is enclosed in triangle brackets. The brackets are not sent with the command string. You must specify a value for the parameter, for example: CURRent 125
Vertical bar |
Used to separate multiple parameter choices for the command string, for example: [SOURce:]CURRent 0 through MAX | MINimum | MAXimum

9.2. SCPI Command Reference List

The subsystems provide more details on all the supported commands. The following table provides a summary of all the available SCPI commands:

SCPI Command Description
MEASure Subsystem  
MEASure[:SCALar]:All[:DC]? Measures and returns the average current, voltage, resistance, and power at the sense location
MEASure[:SCALar]:VOLTage[:DC]? Measures and returns the average voltage at the sense location
MEASure[:SCALar]:CURRent[:DC]? Measures and returns the average current at the sense location
MEASure[:SCALar]:POWer[:DC]? Measures and returns the instantaneous DC power at sense location
MEASure[:SCALar]:RESistance[:DC]? Measures and returns the instantaneous resistance at sense location
INPut Subsystem  
INPut Enables or disables the DC input based on parameter setting
INPut:START Enables the DC input
INPut:STOP Disables the DC input
INPut:PROTection:CLEar Reset soft faults
SOURce Subsystem  
[:SOURce:]SETPoint Sets all set-points using one command
[SOURce:]VOLTage Sets the voltage set-point
[SOURce:]CURRent Sets the current set-point
[SOURce:]POWer Sets the power set-point
[SOURce:]RESistance Sets the resistance set-point
[SOURce:]VOLTage:PROTection:OVER Sets the over voltage trip (OVT) set-point
[SOURce:]CURRent:PROTection:OVER Sets the over current trip (OCT) set-point
[SOURce:]POWer:PROTection:OVER Sets the over power trip (OPT) set-point
[SOURce:]VOLTage:SLEW[:BOTH] Sets the slew rate for rising and falling voltage transitions in voltage regulation
[SOURce:]VOLTage:SLEW:RISE Sets the rising slew rate for voltage when in voltage regulation state
[SOURce:]VOLTage:SLEW:FALL Sets the falling slew rate for voltage when in voltage regulation state
[SOURce:]CURRent:SLEW[:BOTH] Sets the slew rate for both rising and falling transitions in current regulation
[SOURce:]CURRent:SLEW:RISE Sets the rising slew rate for current when in current regulation state
[SOURce:]CURRent:SLEW:FALL Sets the falling slew rate for current when in current regulation state
[SOURce:]POWer:SLEW[:BOTH] Sets the slew rate for both rising and falling power transitions in power regulation
[SOURce:]POWer:SLEW:RISE Sets the rising slew rate for power when in power regulation state
[SOURce:]POWer:SLEW:FALL Sets the falling slew rate for power when in power regulation
[SOURce:]RESistance:SLEW[:BOTH] Sets the slew rate for rising and falling resistance transitions in resistance regulation
[SOURce:]RESistance:SLEW:RISE Sets the rising slew rate for resistance when in resistance regulation state
[SOURce:]RESistance:SLEW:FALL Sets the falling slew rate for resistance when in resistance regulation state
CONFigure Subsystem  
CONFigure:CONTrol Sets the control mode
[:CONFigure]:COMMunication:PROTocol Changes the communication protocol
CONFigure:RANGe Enables extended power range
CONFigure:SENSe Configures the sense location and automated compensation values
SYSTtem Subsystem  
SYSTem:VERSion? Returns hardware revision and firmware version
SYSTem:ERRor[:NEXT]? Returns error type and message
SYSTem:ERRor:COUNt? Returns number of errors in queue
SYSTem:COMMunicate:NETwork:MAC? Returns MAC address
SYSTem:COMMunicate:NETwork:SER Returns Ethernet module serial number
SYSTem:COMMunicate:NETwork:ADDRess Set the static IP address
SYSTem:COMMunicate:NETwork:GATE Set the Gateway IP address
SYSTem:COMMunicate:NETwork:SUBNet Set the subnet IP Mask address
SYSTem:COMMunicate:NETwork:PORT Set the socket number
SYSTem:COMMunicate:NETwork:HOSTname Return hostname
SYSTem:COMMunicate:NETwork:DHCP Set DHCP operation mode
SYSTem:COMMunicate:GPIB:VERSion Returns firmware version of GPIB module
SYSTem:COMMunicate:GPIB:ADDRess Returns address of GPIB module
STATus Subsystem  
*CLS Clear all status registers
*ESE? Configure Event Status Enable Register
*ESR? Read Event Status Register
*ESR? Bit values for the running state
*IDN? Product identification
*OPC Operation Complete Bit
STATus:QUEStionable:CONDition? Returns the value of the Questionable Status register
*RST Reset to factory default states
*SRE Service Request Enable Register
*STB Status Byte
STATus:REGister? Status Register
*TST Execute self-test
*WAI Wait till complete

9.3. CONFiguration Subsystem

9.3.1. CONFigure:CONTrol

This command configures the MagnaLOAD electronic load’s control mode. Control Modes provides more information about the various options.

Command Syntax:CONFigure:CONTrol <NR1>
Parameters:1 (CURRENT) | 2 (VOLTAGE) | 3 (RESISTANCE) | 4 (POWER) | 5 (RHEOSTAT) | 6 (SHUNTREG)
Examples:CONF:CONT 1
*RST Value:1 (CURRENT)
Query Syntax:CONFigure:CONTrol?
Return Param:<NR1>

9.3.2. CONFigure:LOCK

This command configures the MagnaLOAD electronic load’s lock state. While locked, the stop button is the only functional button on the front panel. See Lock for more details on how lock works and how behaves relative to other locking inputs (front panel and digital input).

Command Syntax:CONFigure:LOCK <bool>
Parameters:0 (OFF) | 1 (ON)
Examples:CONF:LOCK 1, CONF:LOCK 0
*RST Value:N/A
Query Syntax:CONFigure:LOCK?
Return Param:<NR3>

9.3.3. [:CONFigure]:COMMunication:PROTocol

This command configures the communications protocol. At startup MagnaLOAD electronic load starts with Standard Commands for Programmable Instruments (SCPI), which is assigned to value 0. Value 1 changes communications to a proprietary protocol called MagnaLINK. This binary messaging protocol only used by Magna-Power software for higher-speed applications. The unit will revert back to SCPI protocol upon reset.

Command Syntax:[:CONFigure]:COMMunication:PROTocol <NR1>
Parameters:0 (SCPI) | 1 (MagnaLINK)
Examples:COMM:PROT 1
*RST Value:1 (VOLTAGE)
Query Syntax:CONFigure:CONTrol?
Return Param:<NR1>

9.3.4. CONFigure:SENSe

This command configures where the MagnaLOAD electronic load senses voltage. The sense location also effects how power and resistance are calculated. Local sensing monitors the directly across the output terminals. Remote sensing, as described in remote-sense, measures across the terminal JS2. This external connection can be used to improve regulation at the point of load, as is needed for example, in compensating voltage drops caused by wire resistance.

Command Syntax:CONFigure:SENSe <NR1>
Parameters:0 (local) | 1 (remote)
Examples:CONF:SENS 1
*RST Value:N/A
Query Syntax:CONFigure:SENS?
Return Param:<NR1>

9.3.5. CONFigure:SOURce

The command selects and routes different set points sources to the digital controller. Operation of this feature is described in Set Point Source. By default, the source is set to local (value 0), where set points originating from the front panel or communication interfaces are routed to the ARx Series digital control. When the source is set to function generator (value 1), set points are generated internally, by a periodic function generator block. When external analog input (value 3) is set, the voltage(s) applied to the rear connector are converted into set points.

Command Syntax:CONFigure:SOURce <NR1>
Parameters:0 (local) | 1 (function generator) | 2 (external analog input)
Examples:CONF:SOUR 1
*RST Value:0 (local)
Query Syntax:CONFigure:SOURce?
Return Param:<NR1>

9.3.6. CONFigure:RANGe

This command activates a programmable series resistance and is available only in ARx and WRx models. When enabled, power dissipation is shared across series resistors and linear devices allowing the product to reach higher power levels.

Command Syntax:CONFigure:RANGe <NR1>
Parameters:0 (low power) | 1 (high power)
Examples:CONF:RANG 1
*RST Value:0 (local)
Query Syntax:CONFigure:RANGe?
Return Param:<NR1>

9.4. MEASure Subsystem

9.4.1. MEASure[:SCALar]:All[:DC]?

This query command returns the average measurements as a list for current, voltage, power, and resistance, respectively.

Query Syntax:MEASure[:SCALar]:ALL[:DC]?
Examples:MEAS:ALL?, MEASURE:ALL:DC?
Return Param:<NR2>, <NR2>, <NR2>, <NR2>

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

This query commands commands the MagnaLOAD electronic load to measure and return the average voltage at the DC terminals. If the remote sense function is used and engaged, this command returns the voltage measured at the sense terminals.

Query Syntax:MEASure:VOLTage[:DC]?
Examples:MEAS:VOLT?, MEASURE:VOLTAGE:DC?
Return Param:<NR2>

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

This query commands the MagnaLOAD electronic load to measure and return the average current through the DC terminals.

Query Syntax:MEASure[:SCALar]:CURRent[:DC]?
Examples:MEAS:CURR?, MEASURE:CURRENT:DC?
Return Param:<NR2>

9.4.4. MEASure[:SCALar]:POWer[:DC]?

This query commands commands the MagnaLOAD electronic load to measure and return the average power at the DC terminals.

Query Syntax:MEASure:POWer[:DC]?
Examples:MEAS:POW?, MEASURE:POWER:DC?
Return Param:<NR2>

9.4.5. MEASure[:SCALar]:RESistance[:DC]?

This query commands commands the MagnaLOAD electronic load to measure and return the average power at the DC terminals.

Query Syntax:MEASure:RESistance[:DC]?
Examples:MEAS:RES?, MEASURE:RESISTANCE:DC?
Return Param:<NR2>

9.5. INPut Subsystem

The INPut Subsystem is an aliased version of the SCPI Standard’s OUTPut subsystem. From the SCPI Standard:

A source which is sourcing impedance (programmable load) is allowed to alias this subsystem as INPut, providing that the OUTPut keyword is also recognized and the INPut subsystem is not used for its intended purpose within the instrument.

9.5.1. INPut

This command enables or disables the MagnaLOAD electronic load input. The state of a disabled input is a high impedance condition.

Command Syntax:INPut[:STATe] <bool>
Parameters:0 (OFF) | 1 (ON)
Examples:INP 1, INP:STAT ON
Alias:OUTPut[:STATe] <bool>
*RST Value:0 (OFF)

9.5.2. INPut:START

This command enables MagnaLOAD electronic load input. The START command mirrors the front panel Start button functionality, providing an alternative to the parameter-based INPut command.

Command Syntax:INPut:START
Parameters:None
Examples:INP:START
Alias:OUTPut:START
*RST Value:N/A

9.5.3. INPut:STOP

This command disables MagnaLOAD electronic load input. The STOP command mirrors the front panel Stop button functionality, providing an alternative to the parameter-based INPut command.

Command Syntax:INPut:STOP
Parameters:None
Examples:INP:STOP
Alias:OUTPut:STOP
*RST Value:N/A

9.5.4. INPut:PROTection:CLEar

This commands removes the latch that disables the input when a fault condition is detected, as further detailed in Clear Command documentation. All conditions that generate the fault must be resolved before the latch can be cleared. Once the fault has been cleared, the input can be re-enabled with the INPut:START command.

Command Syntax:INPut:PROTection:CLEar
Parameters:None
Examples:INP:PROT:CLE
Alias:OUTPut:PROTection:CLEar
*RST Value:N/A

9.6. SOURce Subsystem

9.6.1. [:SOURce:]SETPoint

This command programs all set-points using the list of values: current, voltage, power, and resistance, respectively.

Command Syntax:[:SOURce]:SETPoint <NRf+>[mA|A], <NRf+>[mV|V], <NRf+>, <NRf+>
Parameters:0 through MAX | MINimum | MAXimum
Examples:SETPT 1.0, 1000.0, 1250.0, 1795.0
*RST Value:MINimum
Query Syntax:[:SOURce]:SETPoint?
Return Param:<NR2>

9.6.2. [SOURce:]CURRent

This command programs the current set-point that the MagnaLOAD electronic load will regulate to when operating in constant current mode.

Command Syntax:[SOURce:]CURRent <NRf+>
Parameters:0 through MAX | MINimum | MAXimum
Examples:CURR 0.5, CURR 5
*RST Value:MINimum
Query Syntax:[SOURce:]CURRent?
Return Param:<NR3>

9.6.3. [SOURce:]POWer

This command programs the power set-point, in watts, which the MagnaLOAD electronic load will regulate to when operating in constant power mode.

Command Syntax:[SOURce:]POWer <NRf+>
Parameters:0 through MAX | MINimum | MAXimum
Examples:POW 223.6, POW 5225
*RST Value:MINimum
Query Syntax:[SOURce:]POWer?
Return Param:<NR3>

9.6.4. [SOURce:]VOLTage

This command programs the voltage set-point, in volts, which the MagnaLOAD electronic load will regulate to when operating in constant voltage mode.

Command Syntax:[SOURce:]VOLTage <NRf+>
Parameters:0 through MAX | MINimum | MAXimum
Examples:VOLT 223.6, POW 5225
*RST Value:MINimum
Query Syntax:[SOURce:]VOLTage?
Return Param:<NR3>

9.6.5. [SOURce:]RESistance

This command programs the resistance set-point, in ohms, which the MagnaLOAD electronic load will regulate to when operating in constant resistance mode.

Command Syntax:[SOURce:]RESistance <NRf+>
Parameters:0 through MAX | MINimum | MAXimum
Examples:RES 223.6, POW 5225
*RST Value:MINimum
Query Syntax:[SOURce:]RESistance?
Return Param:<NR3>

9.6.6. [SOURce:]VOLTage:PROTection:OVER

This command programs the over voltage trip (OVT) set-point. If the input voltage exceeds the over voltage trip set-point for multiple samples, the input is disconnected and an OPT fault is indicated.

Command Syntax:[SOURce:]VOLTage:PROTection:OVER <NRf+>
Parameters:0 through MAX | MINimum | MAXimum
Examples:VOLT:PROT:OVER 662.2
*RST Value:MAXimum
Query Syntax:[SOURce:]VOLTage:PROTection:OVER?
Return Param:<NR3>

9.6.7. [SOURce:]CURRent:PROTection:OVER

This command programs the over current trip (OCT) set-point. If the input current exceeds the over current trip set-point for multiple samples, the input is disconnected and an OCT fault is indicated.

Command Syntax:[SOURce:]CURRent:PROTection:OVER <NRf+>
Parameters:0 through MAX | MINimum | MAXimum
Examples:CURR:PROT:OVER 25.00
*RST Value:MAXimum
Query Syntax:[SOURce:]CURRent:PROTection:OVER?
Return Param:<NR3>

9.6.8. [SOURce:]POWer:PROTection:OVER

This command programs the over power trip (OPT) set-point. If the input power exceeds the over power trip set-point for multiple sample, the input is disconnected and an OPT fault is indicated.

Command Syntax:[SOURce:]POWer:PROTection:OVER <NRf+>
Parameters:0 through MAX | MINimum | MAXimum
Examples:POW:PROT:OVER 662.2
*RST Value:MAXimum
Query Syntax:[SOURce:]POWer:PROTection:OVER?
Return Param:<NR3>

9.6.9. [SOURce:]VOLTage:SLEW[:BOTH]

This command sets the voltage slew rate for the MagnaLOAD electronic load while in constant voltage regulation. This command programs both rising and falling slew rates, respectively. The units for voltage slew rate are ohms per millisecond. Although any slew rate value may be entered, the MagnaLOAD electronic load selects a slew rate that is closest to the programmed value. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Command Syntax:[SOURce:]VOLTage:SLEW[:BOTH] <NRf+>, <NRf+>
Parameters:1 to MAXimum [V/ms] | MAXimum | MINimum
Examples:VOLT:SLEW MAX, VOLT:SLEW 50,50
*RST Value:MAXimum
Query Syntax:[SOURce:]VOLTage:SLEW[:BOTH]?
Return Param:<NR3>

9.6.10. [SOURce:]VOLTage:SLEW:RISE

This command sets the voltage slew rate for increasing voltage transitions while in constant voltage regulation. The units for voltage slew rate are ohms per millisecond. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Command Syntax:[SOURce:]VOLTage:SLEW:RISE <NRf+>
Parameters:1 to MAXimum [V/ms] | MAXimum | MINimum
Examples:VOLT:SLEW:RISE MAX, VOLT:SLEW:RISE 39
*RST Value:MAXimum
Query Syntax:[SOURce:]VOLTage:SLEW:RISE?
Return Param:<NR3>

9.6.11. [SOURce:]VOLTage:SLEW:FALL

This command sets the voltage slew rate for decreasing voltage transitions while in constant voltage regulation. The units for voltage slew rate are ohms per millisecond. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Command Syntax:[SOURce:]VOLTage:SLEW:FALL <NRf+>
Parameters:1 to MAXimum [V/ms] | MAXimum | MINimum
Examples:VOLT:SLEW:FALL MAX, VOLT:SLEW:FALL 24
*RST Value:MAXimum
Query Syntax:[SOURce:]VOLTage:SLEW:FALL?
Return Param:<NR3>

9.6.12. [SOURce:]CURRent:SLEW[:BOTH]

This command sets the current slew rate for current transitions in constant current regulation. This command programs both rising and falling slew rates, respectively. Although any slew rate value may be entered, the MagnaLOAD electronic load selects a slew rate that is closest to the programmed value. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Command Syntax:[SOURce:]CURRent:SLEW[:BOTH] <NRf+>, <NRf+>
Parameters:1 to MAXimum [A/ms] | MAXimum | MINimum
Examples:CURR:SLEW MAX, CURR:SLEW 0.2, 0.2
*RST Value:MAXimum
Query Syntax:[SOURce:]CURRent:SLEW[:BOTH]?
Return Param:<NR3>

9.6.13. [SOURce:]CURRent:SLEW:RISE

This command sets the current slew rate for increasing current transitions while in constant current regulation. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Command Syntax:[SOURce:]CURRent:SLEW:RISE <NRf+>
Parameters:1 to MAXimum [A/ms] | MAXimum | MINimum
Examples:CURR:SLEW:RISE MAX, CURR:SLEW:RISE 22
*RST Value:MAXimum
Query Syntax:[SOURce:]CURRent:SLEW:RISE?
Return Param:<NR3>

9.6.14. [SOURce:]CURRent:SLEW:FALL

This command sets the current slew rate for decreasing current transitions while in constant current regulation. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Command Syntax:[SOURce:]CURRent:SLEW:FALL <NRf+>
Parameters:1 to MAXimum [A/ms] | MAXimum | MINimum
Examples:CURR:SLEW:FALL MAX, CURR:SLEW:FALL 22
*RST Value:MAXimum
Query Syntax:[SOURce:]CURRent:SLEW:FALL?
Return Param:<NR3>

9.6.15. [SOURce:]POWer:SLEW[:BOTH]

This command sets the power slew rate for the MagnaLOAD electronic load while in constant power regulation. This command programs both rising and falling slew rates, respectively. The units for power slew rate are watts per millisecond. Although any slew rate value may be entered, the MagnaLOAD electronic load selects a slew rate that is closest to the programmed value. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Command Syntax:[SOURce:]POWer:SLEW[:BOTH] <NRf+>, <NRf+>
Parameters:1 to MAXimum [W/ms] | MAXimum | MINimum
Examples:POW:SLEW MAX, POW:SLEW 50, 50
*RST Value:MAXimum
Query Syntax:[SOURce:]POWer:SLEW[:BOTH]?
Return Param:<NR3>

9.6.16. [SOURce:]POWer:SLEW:RISE

This command sets the power slew rate for increasing power transitions while in constant power regulation. The units for power slew rate are watts per millisecond. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Command Syntax:[SOURce:]POWer:SLEW:RISE <NRf+>
Parameters:1 to MAXimum [W/ms] | MAXimum | MINimum
Examples:POW:SLEW:RISE MAX, POW:SLEW:RISE 39
*RST Value:MAXimum
Query Syntax:[SOURce:]POWer:SLEW:RISE?
Return Param:<NR3>

9.6.17. [SOURce:]POWer:SLEW:FALL

This command sets the power slew rate for decreasing power transitions while in constant power regulation. The units for power slew rate are watts per millisecond. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Command Syntax:[SOURce:]POWer:SLEW:FALL <NRf+>
Parameters:1 to MAXimum [W/ms] | MAXimum | MINimum
Examples:POW:SLEW:FALL MAX, POW:SLEW:FALL 24
*RST Value:MAXimum
Query Syntax:[SOURce:]POWer:SLEW:FALL?
Return Param:<NR3>

9.6.18. [SOURce:]RESistance:SLEW[:BOTH]

This command sets the resistance slew rate for the MagnaLOAD electronic load while in constant resistance regulation. This command programs both rising and falling slew rates, respectively. The units for resistance slew rate are ohms per millisecond. Although any slew rate value may be entered, the MagnaLOAD electronic load selects a slew rate that is closest to the programmed value. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Command Syntax:[SOURce:]RESistance:SLEW[:BOTH] <NRf+>, <NRf+>
Parameters:1 to MAXimum [Ω/ms] | MAXimum | MINimum
Examples:RES:SLEW MAX, RES:SLEW 50
*RST Value:MAXimum
Query Syntax:[SOURce:]RESistance:SLEW[:BOTH]?
Return Param:<NR3>

9.6.19. [SOURce:]RESistance:SLEW:RISE

This command sets the resistance slew rate for increasing resistance transitions while in constant resistance regulation. The units for resistance slew rate are ohms per millisecond. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Command Syntax:[SOURce:]RESistance:SLEW:RISE <NRf+>
Parameters:1 to MAXimum [Ω/ms] | MAXimum | MINimum
Examples:RES:SLEW:RISE MAX, RES:SLEW:RISE 39
*RST Value:MAXimum
Query Syntax:[SOURce:]RESistance:SLEW:RISE?
Return Param:<NR3>

9.6.20. [SOURce:]RESistance:SLEW:FALL

This command sets the resistance slew rate for decreasing resistance transitions while in constant resistance regulation. The units for resistance slew rate are ohms per millisecond. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Command Syntax:[SOURce:]RESistance:SLEW:FALL <NRf+>
Parameters:1 to MAXimum [Ω/ms] | MAXimum | MINimum
Examples:RES:SLEW:FALL MAX, RES:SLEW:FALL 24
*RST Value:MAXimum
Query Syntax:[SOURce:]RESistance:SLEW:FALL?
Return Param:<NR3>

9.7. STATus Subsystem

Status commands let you determine the condition of the MagnaLOAD electronic load at any time, grouping together multiple feedback parameters into one returned value.

9.7.1. *CLS

This command clears all status register (ESR, STB and error queue).

Command Syntax:*CLS
Parameters:None
Examples:*CLS
Return Param:None
*RST Value:N/A

9.7.2. *ESE?

This command programs the Event Status Enable Register (ESE). The programming determines which events of the Event Status Register (ESR) set the Event Status Bit (ESB) of the Status Byte Register (STB). A “1” in the bit position enables the corresponding event. All of the enabled events of the ESE are logically OR’d to cause the ESB of the STB to be set.

Command Syntax:*ESE <NR1>
Parameters:Register Bit Position
Examples:*ESE 255
Query Syntax:*ESE?
Return Param:<NR1>
*RST Value:N/A

9.7.3. *ESR?

This query reads the Event Status Register (ESR). After reading the ESR, the register is cleared. The bit configuration of the ESR is the same as the Event Status Enable Register (*ESE). The return parameter is weighted as shown in table below.

The Power On Bit (PON) is set every time the MagnaLOAD electronic load is reset. It can be used to detect a power outage or MagnaLOAD electronic load reset.

Command Syntax:*ESR?
Parameters:None
Examples:*ESR?
Return Param:<NR1>
*RST Value:N/A

Event Status Register

Bit Weight Abbreviation Description
0 1 OPC Operation Complete
1 2 NU Not Used
2 4 QYE Query Error
3 8 DDE Device Dependent Error
4 16 EXE Execution Error
5 32 CME Command Error
6 64 NU Not Used
7 128 PON Power On Event, 1 after power on

9.7.4. *IDN?

This query requests MagnaLOAD electronic load to identify itself, returning a string composed of three fields separated by commas.

Query Syntax:*IDN?
Examples:*IDN?
Return Param:Company Name, MagnaLOAD electronic load Model, Serial Number, Firmware Version
Return Example:Magna-Power Electronics Inc., ARx16.75-1000-14, 1201-0001, 0.029
*RST Value:N/A

9.7.5. *OPC

This command clears the operation complete bit found in the event status register (ESR). Should be used in application programming when delay exists between sending a SCPI command and the execution of the command. When all commands have completed, the OPC bits gets set back to 1.

Query Syntax:*OPC?
Examples:*OPC
Return Param:<NR1>
*RST Value:N/A

9.7.6. *RST

This command resets the various settings and functions in the MagnaLOAD electronic load to their factory default state. This command is commonly used in initialization routines to restore the MagnaLOAD electronic load to a known configuration. Factory default settings for each command are indicated in the description for respective SCPI commands. SCPI commands with RST Value indicated as *N/A either are not affected by the *RST or do not have a parameter that can be changed.

Command Syntax:*RST
Parameters:None
Examples:*RST
*RST Value:N/A

9.7.7. *SRE

This command sets the Service Request Enable Register (SRE). This register, defined in the table “Service Request Enable Register”, determines which bits from the Status Byte Register (see *STB for its bit configuration) are allowed to set the Service Request (RQS) Bit. A 1 in any SRE bit position enables the corresponding Status Byte Register bit. All Status Byte Register enabled bits are then logically OR’d and placed in bit 6 of the Status Byte Register. When *SRE is cleared (by programming it with 0), the power supply cannot generate a service request to the controller.

Command Syntax:*SRE
Parameters:Register Bit Position
Examples:*SRE 20
Query Syntax:*SRE?
Return Param:<NR1>
*RST Value:N/A

Service Request Enable Register

Bit Weight Abbreviation Description
0 1 NU Not Used
1 2 NU Not Used
2 4 NU Not Used
3 8 QUES Questionable Status Bit
4 16 MAV Message Available Bit
5 32 ESB Event Status Bit
6 64 RQS Request Service Bit
7 128 NU Not Used

9.7.8. *STB

This query gets the Status Byte (STB). Registers are cleared only when the signals feeding it are cleared.

Command Syntax:*STB?
Parameters:None
Examples:*STB?
Return Param:<NR1>
*RST Value:N/A

9.7.9. *TST

Executes a self-test routine that validates the operational condition of the MagnaLOAD electronic load. If all tests pass, a 0 is returned, if any test fails, 1 is returned.

Command Syntax:*TST?
Parameters:None
Examples:*TST?
Return Param:<NR1>
*RST Value:N/A

9.7.10. *WAI

Buffer commands until all previous commands have completed execution.

Command Syntax:*WAI
Parameters:None
Examples:*TST;*WAIT*;INP:START
Return Param:N/A
*RST Value:N/A

9.7.11. STATus:QUEStionable:CONDition?

This command queries and returns the values of the Questionable Register. This read-only register holds the live (unlatched) questionable statuses of the MagnaLOAD electronic load. Issuing this query does not clear the register. The bit configuration of the Questionable Register is shown in the table below.

Query Syntax:STATus:QUEStionable:CONDition?
Parameters:None
Examples:STAT:QUES:COND?
Return Param:<bit value>
*RST Value:No Effect

Questionable Register

Bit Weight Abbreviation Description
0 1 OVP over voltage protection, hard fault
1 2 OCT over current trip, soft fault
2 4 OVT over voltage trip, soft fault
3 8 OPT over power trip, soft fault
4 16 OCP over current protection, hard fault
5 32 OTP over temperature protection, hard fault
6 64 RSL remote sense loss, hard fault
7 128 CC constant current regulation, regulation status
8 256 CV constant voltage regulation, regulation status
9 512 CR constant resistance regulation, regulation status
10 1024 CP constant power regulation, regulation status
11 2048 SFLT soft fault, the ord value of all soft faults
12 4096 HFLT hard fault, the ord value of all hard faults

9.7.12. STATus:REGister?

This command queries the Status Register. This read-only register holds the live (unlatched) operation status of the MagnaLOAD electronic load. Issuing a query does not clear the register. The register location and definitions are subject to change after any firmware release to accommodate new features. The Questionable Register is a subset of the status register and does not change between firmware updates. The present bit assignments are shown in the table below.

Status Register

Bit Weight Name Description
0 1 standby output is in standby
1 2 live output is active
2 4 nonhalt1 available
3 8 nonhalt2 available
4 16 overCurrTrip over current trip
5 32 overVoltTrip over voltage trip
6 64 overPwrTrip over power trip
7 128 remoteSenseLoss remote sense voltage outside of acceptable bounds
8 256 underVoltTrip under voltage trip
9 512 shutdown target is creating a shutdown condition
10 1024 linPwrLim power across linear modules exceed ratings
11 2048 resPwrLim power across resistors exceed ratings
12 4096 bootFailure one or multiple target did not boot up
13 8192 bootState one or more targets are waiting to boot
14 16384 phaseCurr rated phase current exceeded
15 32768 comm communications are corrupted
16 65536 overCurrProtect terminal current exceeded product rating
17 131072 overVoltProtect terminal voltage exceeded product rating
18 262144 tempRLin linear module exceeded temperature
19 524288 blownFuse fuse is blown on the auxiliary power supply
20 1048576 interlock available
21 2097152 haltNoReset3 available
22 4194304 haltNoReset4 available
23 8388608 tempDMod diode modules exceeded temperature
24 16777216 invalidProdConfig invalid product configuration
25 33554432 stackOverflow exceeded firmware stack
26 67108864 illegalIsr illegal isr (buffer overflow)
27 134217728 tempRMod resistor module exceeded temperature
28 268435456 belowRatedMinVolt below minimum voltage rating(28)
29 536870912 outOfRegulation out of regulation, unexpected currents measured
30 1073741824 targetUpgrade mainctrl upgrading other targets
31 2147483648 haltSelfClear available
32 4294967296 constantCurr regulation state
33 8589934592 constantVolt regulation state
34 17179869184 constantRes regulation state
35 34359738368 constantPwr regulation state
36 68719476736 powerRange operation range
37 137438953472 remoteSense sense terminal in use
38 274877906944 lock lock state
39 549755813888 extAnlgCtrl external control through analog inputs
40 1099511627776 overTemp temperature fault linear and resistor combined
41 2199023255552 softTripShutdown protection trip caused due to soft faults
42 4398046511104 hardTripShutdown protection trip caused due to hard faults
43 8796093022208 notUsed1 available
44 17592186044416 notUsed2 available
45 35184372088832 notUsed3 available
46 70368744177664 notUsed4 available
47 140737488355328 notUsed5 available
48 281474976710656 notUsed6 available
49 562949953421312 notUsed7 available
50 1125899906842624 notUsed8 available
51 2251799813685248 notUsed9 available
52 4503599627370496 notUsed10 available
53 9007199254740992 notUsed11 available
54 1.801439850948198e+16 notUsed12 available
55 3.602879701896397e+16 notUsed13 available
56 7.205759403792794e+16 notUsed14 available
57 1.441151880758559e+17 notUsed15 available
58 2.882303761517117e+17 notUsed16 available
59 5.764607523034235e+17 notUsed17 available
60 1.152921504606847e+18 notUsed18 available
61 2.305843009213694e+18 notUsed19 available
62 4.611686018427388e+18 notUsed20 available
63 9.223372036854776e+18 notUsed21 available
Query Syntax:STATus:REGister?
Parameters:None
Examples:STAT:REG?
Return Param:<NR1>
*RST Value:No Effect

9.8. SYSTem Subsystem

9.8.1. SYSTem:VERSion?

The SYST:VERS? query returns the MagnaLOAD electronic load’s bootloader, firmware, and hardware revision, respectively. The returned value is a comma-separated list of values.

Query Syntax:SYSTem:VERSion?
Examples:SYST:VERS?, SYSTEM:VERSION?
Return Param:<NR2>, <NR2>, <NR2>

9.8.2. SYSTem:ERRor[:NEXT]?

The SYST:ERR? query returns the error type and message that occurred in the system. The format of the return string is an error number followed by corresponding error message string. The errors are stored in a FIFO (first-in, first-out) buffer. As the errors are read, they are removed from the queue. When all errors have been read, the query returns 0, “NO ERROR.” If more errors have accumulated than the queue can hold, the last error in the queue will be -350, “Queue Overflow.” When system errors occur, the Standard Event Status Register (ESR), records the error groups as defined in the table Error Bits table below. The Error Message table below lists system errors that are associated with SCPI syntax errors and with interface problems.

Query Syntax:SYSTem:ERRor?
Examples:SYST:ERR?, SYSTEM:ERROR?
Return Param:<error code>, <”error string”>

Standard Event Status Register Error Bits

Bit Error Code Error Type
5 100 through -199 Command
4 200 through -299 Execution
3 300 through -399 Device dependent
2 400 through -499 Query

Error Messages

Bit Error String Error Error Description
-100 Command error Generic Command error
-102 Syntax error Unrecognized command or data type
-108 Parameter not allowed Too many parameters
-222 Data out of range Value provided outside device’s range
-350 Queue overflow Errors lost due to too many errors in queue
-400 Query Error Generic query error

9.8.3. SYSTem:ERRor:COUNt?

This query reads the number of errors in the error queue.

Query Syntax:SYSTem:ERRor:COUNt?
Examples:SYST:ERR:COUN?
Return Param:<NR1>

9.8.4. SYSTem:COMMunicate:NETwork:VERSion?

This query reads the firmware and hardware versions of the Ethernet communications module. :Query Syntax: [SYSTem][:COMMunicate]:NETwork:VERSion? :Examples: SYST:COMM:NET:VERS?, NET:VERS? :Return Param: <Firmware Ver. XX.Y, Hardware Rev. XX.Y>

Description This query is available only for units with the IEEE-488 GPIB (+GPIB) option installed. This query reads the firmware version of the GPIB communication module. Query Syntax [SYSTem][:COMMunicate]:GPIB:VERSion? Examples SYST:COMM:GPIB:VERS? GPIB:VERS? Returned Parameter <Firmware Ver. XX.Y>

9.8.5. SYSTem:COMMunicate:NETwork:MAC?

This query returns the MAC address of the Ethernet module. MAC address consist of two number groups: the first three bytes are known as the Organizationally Unique Identifier (OUI), which is distributed by the IEEE, and the last three bytes are the device’s unique serial number. The six bytes are separated by hyphens. The MAC address is unique to the instrument and cannot be altered by the user.

Query Syntax:[SYSTem][:COMMunicate]:NETwork:MAC?
Examples:SYST:COMM:NET:MAC?, NET:MAC?
Return Param:<XX-XX-XX-YY-YY-YY>

9.8.6. SYSTem:COMMunicate:NETwork:SER

This command sets the serial number of the Ethernet module. The serial number is an integer ranging from 1 to 16777215 and cannot be altered by the user.

Query Syntax:[SYSTem][:COMMunicate]:NETwork:SER?
Examples:SYST:COMM:NET:SER?, NET:SER?
Return Param:<NR1>

9.8.7. SYSTem:COMMunicate:NETwork:ADDRess

This command sets the static address of the Ethernet module of the MagnaLOAD electronic load. The factory default address setting is 192.168.1.100.

Command Syntax:[SYSTem][:COMMunicate]:NETwork:ADDRess <string>
Parameters:IP address is represented with 4 bytes each having a range of 0-255 separated by periods
Examples:SYSTem:COMM:NET:ADDR 192.168.10.2, NET:ADDR 192.168.10.2
Query Syntax:[SYSTem][:COMMunicate]:NETwork:ADDRess?
Return Param:<string>

9.8.8. SYSTem:COMMunicate:NETwork:GATE

This command sets the Gateway IP address of the Ethernet module of the MagnaLOAD electronic load. The factory default Gateway IP setting is 192.168.1.1.

Command Syntax:[SYSTem][:COMMunicate]:NETwork:GATE <string>
Parameters:Gateway IP address is represented with 4 bytes each having a range of 0-255 separated by dots
Examples:SYSTem:COMM:NET:GATE 192.168.10.2, NET:GATE 192.168.10.2
Query Syntax:[SYSTem][:COMMunicate]:NETwork:GATE?
Returned Param:<string>

9.8.9. SYSTem:COMMunicate:NETwork:SUBNet

This command sets the subnet IP Mask address of the Ethernet module of the MagnaLOAD electronic load. The factory subnet mask setting is 255.255.255.0.

Command Syntax:[SYSTem][:COMMunicate]:NETwork:SUBNet <string>
Parameters:IP mask address is represented with 4 bytes each having a range of 0-255 separated by periods.
Examples:SYSTem:COMM:NET:SUBNet 255.255.255.128, NET: SUBNet 255.255.255.128
Query Syntax:[SYSTem][:COMMunicate]:NETwork:SUBNet?
Returned Parameter:
 <string>

9.8.10. SYSTem:COMMunicate:NETwork:PORT

This command sets the Socket (Port) of the Ethernet module of the MagnaLOAD electronic load. The factory default port setting is 50505. The factory recommends port values greater than 49151 to avoid conflicts with registered Ethernet port functions.

Command Syntax:[SYSTem][:COMMunicate]:NETwork:PORT <NR1>
Parameters:16-bit socket number (1 to 65,535)
Examples:SYSTem:COMM:NET: PORT 50505, NET: PORT 50505
Query Syntax:[SYSTem][:COMMunicate]:NETwork:PORT?
Returned Param:<NR1>

9.8.11. SYSTem:COMMunicate:NETwork:HOSTname

This query reads the host name of the Ethernet communications module. :Query Syntax: [SYSTem][:COMMunicate]:NETwork:HOSTname? :Examples: SYST:COMM:NET:HOST?, NET:HOST? :Returned Param: <string>

9.8.12. SYSTem:COMMunicate:NETwork:DHCP

This command sets the DHCP operating mode of the Ethernet module. If DHCP is set to 1, the module will allow its IP address to be automatically set by the DHCP server on the network. If DHCP is set to 0, the default IP address is set according to .

Command Syntax:[SYSTem][:COMMunicate]:NETwork:DHCP <NR1>
Parameters:0 (DHCP Off) | 1 (DHCP On)
Examples:SYST:COMM:NET:DHCP 0, NET:DHCP 1
Query Syntax:[SYSTem][:COMMunicate]:NETwork:DHCP?
Returned Param:<NR1>

9.8.13. SYSTem:COMMunicate:GPIB:VERSion

This query is available only for units with the IEEE-488 GPIB (+GPIB) option installed. This query reads the firmware version of the GPIB communication module.

Query Syntax:[SYSTem][:COMMunicate]:GPIB:VERSion?
Examples:SYST:COMM:GPIB:VERS?, GPIB:VERS?
Returned Param:<Firmware Ver. XX.Y>

9.8.14. SYSTem:COMMunicate:GPIB:ADDRess

This command is available only for units with the IEEE-488 GPIB (+GPIB) option installed. This command sets the address of the GPIB module of the MagnaLOAD electronic load. The address can be 1 to 30 where address 0 is normally assigned to the GPIB Master. The factory default address is 1.

Command Syntax:[SYSTem][:COMMunicate]:GPIB:ADDRess <NR1>
Parameters:1 - 30
Examples:SYST:COMM:GPIB:ADDR 27, GPIB:ADDR 27
Query Syntax:[SYSTem][:COMMunicate]:GPIB:ADDR?
Returned Param:<NR1>