SCPI COMMAND REFERENCE
The Keithley 2651A is Keithley's source measure unit in the Model 2651A High Power System SourceMeter family. Its SCPI remote-control interface exposes 20 commands across 3 subsystems - 13 settable and 7 queries - and every command is documented here with its parameters, accepted values, return format, and a copy-paste PyVISA example for automating test and measurement.
20
Commands
13
Settable
7
Queries
3
Subsystems
SCPI
Verified
2026-07-16
Selects the output-off mode for the source-measure unit. The mode can be normal, high-impedance, or zero; the manual also shows remote-interface constants for normal and high-Z selection.
| Name | Type | Values | Description |
|---|---|---|---|
| mode | enum | NORMAL | HI-Z | ZERO | Output-off mode to select. |
Selects the output-off function used when the output is turned off in NORMAL output-off mode. The function can be set to CURRENT or VOLTAGE; VOLTAGE is the default.
| Name | Type | Values | Description |
|---|---|---|---|
| mode | enum | CURRENT | VOLTAGE | Sets the output-off function. |
Sets the output-off current limit used for the voltage source when the output-off mode is normal. The manual describes it as the smua.source.offlimiti attribute and shows it being assigned a current value remotely.
| Name | Type | Values | Description |
|---|---|---|---|
| iValue | real | - | Current limit value for NORMAL output-off mode. |
smua.source.offlimiti = iValue
Sets the voltage output-off limit used in normal output-off mode. It corresponds to the smua.source.offlimitv attribute, which specifies the voltage limit for the current source.
| Name | Type | Values | Description |
|---|---|---|---|
| vValue | real | - | Voltage limit to use in normal output-off mode. |
Loads and runs a named script immediately. If no name is provided, the command creates the anonymous script.
| Name | Type | Values | Description |
|---|---|---|---|
| scriptName | string | - | Name of the script to load and run; it must be a legal Lua variable name. |
Retrieves the identification string. The string includes the manufacturer, model number, serial number, and firmware revision level.
*IDN?
Sets the OPC bit in the Standard Event Register when all pending overlapped commands complete. It is used to wait for pending overlapped commands to finish.
Places an ASCII "1" in the output queue when all previous overlapped commands complete. It is used to wait for pending overlapped commands to complete.
Returns the instrument to default conditions.
Generates a command interface trigger event for the trigger model.
Requests self-test results. This compatibility command always places a zero (0) in the output queue; the instrument does not actually perform a self-test.
Suspends execution of subsequent commands until all previously overlapped commands have finished.
*WAI
Resets the bits of the event and NTR registers to 0, sets all PTR register bits on, and clears the output queue.
Programs the Standard Event Status Enable register. The value is sent as a numeric mask; each bit in the register is set according to the decimal value provided.
| Name | Type | Values | Description |
|---|---|---|---|
| mask | integer | 0 - 65535 | Decimal value used to program the register bits. |
*ese 1169
Returns the Status Byte Register. For the *STB? common command, bit B6 is the MSS bit.
Programs the Service Request Enable Register. Use 0 to reset the register bits to 0; the mask range is 0 to 255.
| Name | Type | Values | Description |
|---|---|---|---|
| mask | integer | 0 - 255 | Mask value written to the Service Request Enable Register. |
Reads the Service Request Enable Register. The returned numeric value indicates which bits are set.
Programs the Event Status Enable Register. The mask can be set from 0 to 255.
| Name | Type | Values | Description |
|---|---|---|---|
| mask | integer | 0 - 255 | Event status enable mask. |
Reads the Event Status Enable Register.
Reads the Standard Event Status Register.
