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3.4.14 disable_testing_mode

The disable_testing_mode command is used to exit the testing mode. The sensor is not in testing mode when

the 2nd most significant bit of Byte 10 from the read_measurement (Section 3.4.3) output is equal to 0.

Command

Command

Hex Code

Argument

Consecutive Read

Execution

Time (ms)

Description

disable_testi

ng_mode

0x3F3D

-

-

-

Disables the testing mode.

3.4.15 perform_forced_recalibration

The perform_forced_recalibration command (FRC) is used to correct the sensor’s CO2 concentration output with

an externally provided target CO2 concentration. Ensure the sensor reading and environmental conditions,

including CO2 concentration, are stable for the duration of the recommended operation sequence. See Section

3.5 for the signal output and input conversion. Accepted input values are between 0 – 32’000 ppm.

Command

Command

Hex Code

Argument

Consecutive Read

Execution

Time (ms)

Description

perform_for

ced_recalibr

ation

0x362F

Byte0: Target CO2

concentration 8msb

Byte1: Target CO2

concentration 8lsb

Byte2: CRC

Byte0: CO2 concentration

correction 8msb

Byte1: CO2 concentration

correction 8lsb

Byte2: CRC

90

Performs FRC to the

target CO2

concentration. Failed

command execution

will return 0xFFFF.

Recommended operation sequence:

1. Operate the sensor for a minimum of 30 s in continuous mode or 30 single shot measurements,

corresponding to 5 minutes in single shot measurement mode with a 10 s sampling interval. For sampling

intervals higher than 10 s, increase the operation time accordingly.

2. If operating in continuous mode, send the stop_continuous_measurement command (Section 3.4.2) and wait

for the specified execution time. Else if operating in single shot mode, the sensor must remain in idle mode,

i.e., must not be sent to sleep mode, after operation.

3. Send the perform_forced_recalibration command with the target CO2 concentration and optionally read out

the applied FRC correction.

3.4.16 get_product_id

The get_product_ID command can be used to identify the sensor and verify the communication.

Command

Command

Hex Code

Argument

Consecutive Read

Execution

Time (ms)

Description

Get_product

_id

0x365B

-

6 x (2 Bytes + 1 CRC)

1

Returns a 32-bit product ID

and 64-bit unique serial

number.

Product

Product ID

STCC4

0x0901018A