7.2. Error and Status Messages

The following are error and status messages that may be displayed by the M81-SSM during operation.

SCPI Error Messages

Critical startup errors:

The following are errors that may be displayed during startup. These errors are critical and will prevent the M81-SSM from functioning properly. Please contact Lake Shore Service for support see Technical Inquiries for more information.

Error	SCPI error code	Description
Invalid calibration	-340	The calibration is not valid. The data is either corrupt, uninitialized or default values.
NOVRAM not communicating	-320	Indicates that a NOVRAM device failed to initialize. See Summary of Internal Memory Devices for more information about memory devices.
Model ID not communicating	-300	Indicates that the device used to store the model ID failed to initialize.
Rev ID not communicating	-300	Indicates that the device used to store the revision ID failed to initialize.
Line frequency out of bounds	-300	Indicates the detected line frequency is out of normal operating range. A default value of 60 Hz is used.
ADC config corrupt	-300	Indicates that an invalid internal ADC configuration was detected.
Invalid channel card configuration	-300	Indicates that an invalid channel card configuration was detected. This typically indicates that an expected channel card was not detected.

Runtime errors:

The following are errors that may be displayed during operation. These errors are critical and will prevent the M81-SSM from functioning properly. Please contact Lake Shore Service for support see Technical Inquiries for more information.

Error	SCPI error code	Description
Overflow	-240	Internal data streaming buffer overflow. You can continue, but note that data loss has occurred during a data stream.
Measure module I2C corrupt	-240	Failed readback on the specified measure module I2C write.
Source module I2C corrupt	-240	Failed readback on the specified source module I2C write.
Head temp sensor failure	-240	Failed to communicate with the head board temperature sensor.
Measure module temp sensor failure	-240	Failed to communicate with the specified measure module temperature sensor.
Source module temp sensor failure	-240	Failed to communicate with the specified source module temperature sensor.
Master reference error	-240	The measured master reference voltage is out of bounds.
Source gain max correction	-240	Computed gain factor is out of bounds on the specified source module.
Source offset max correction	-240	Measured offset is too large on the specified source module.
Source DC gain max correction	-240	Computed gain factor is out of bounds on the specified source module’s DC chain.
Source DC offset max correction	-240	Measured offset is too large on the specified source module’s DC chain.
Measure gain max correction	-240	Computed gain factor is out of bounds on the specified measure module.
Measure offset max correction	-240	Measured offset is too large on the specified measure module.
Measure voltage nulling limit	-240	Input offset voltage is too large to correct on the specified measure module.
Measure current nulling limit	-240	Input bias current is too large to correct on the specified measure module.
Measure module JSON checksum	-230	Checksum validation of the specified measure module’s JSON NOVRAM data has failed.
Source module JSON checksum	-230	Checksum validation of the specified source module’s JSON NOVRAM data has failed.
Internal communication error	N/A	Internal communication between the instrument’s microcontrollers or hardware was interrupted. This typically occurs when a module is unplugged without first unloading it. See Module Loading for details on how to properly load and unload modules. When this error is encountered the instrument will attempt to re-estabilish communication. If it is able to do so, an option to continue will be presented ortherwise the instrument will need to be restarted.

Module connect errors:

The following are errors that may be displayed when connected modules are loaded. The module will not function until the error is corrected.

Error	Description
Read error	There was an error identifying the connected module.
Unrecognized module error	The connected module was identified, but is not supported with this firmware version. This can typically be resolved by updating the firmware.
Port direction error	The connected module was plugged into the wrong port. For example, a source module was plugged into a measure port. This can typically be resolved by plugging the module into the correct port type.

Measurement status messages:

The following are status messages that may be displayed during measurement. Readings may not be available when these messages are displayed.

Status	Description
Settling	The measurement is settling due to a hardware change.
Overload	The module is in an active overload.
Unlocked	The module’s lock-in amplifier is unlocked.
V Limit	The module is at its voltage limit.
I Limit	The module is at its current limit.

Self-calibration status messages:

The following are status messages that may be displayed during self-calibration.

Status	Description
In progress	The calibration is in progress. See specific step details.
Initializing step	Getting ready to run calibration.
Learning reference step	Measuring internal reference against external calibrator.
Measuring references step	Measuring internal reference voltage.
Calibrating source step	Calibrating specified source channel.
Calibrating measure step	Calibrating specified measure channel.
Voltage offsets step	Calibrating offset for specified voltage range.
Nulling current step	Calibrating offsets.
Nulling voltage step	Adjusting input offset voltage.
Self-calibration successful	Calibration completed successfully.

Resistance calculation status messages:

The following are status messages that may be displayed during self-calibration.

Status	Description
S MISS	The selected source module is not connected.
S UNL	The selected source module is connected but not loaded.
INVALID	The source module is not compatible with the measure module for calculating resistance. This occurs when the two modules use the same units, such as a VM-10 and VS-10.
E TYPE	The excitation type is not valid. This occurs when the measure mode and source shape do not create a supported resistance calculation.
DIV BY 0	The sourced or measured current is 0.
M ERR	There is an active error on the measure module.
S ERR	There is an active error on the source module.