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Status supported
Source code pce-322a
Connectivity USB/serial
Frequency range 31.5Hz - 8kHz
Measurement range (A) 30dB - 130dB
Resolution 0.1dB
Accuracy (94dB@1kHz) 1.4dB
Frequency weighting A, C
Time weighting F, S
Standards IEC 61672-1 Class 2
Website pce-instruments.com

The PCE PCE-322A is an IEC 61672-1 class 2 compliant sound level meter with USB connectivity.





The device communicates at 115200 baud, no parity, 8 data bits, and 1 stop bit (115200/8n1).


None of the following commands are needed to receive live measurements from the device; see the next section.

The commands are always 2 byte and take no parameters, except for the one requesting memory blocks.

The following commands are supported:

Command Description
0xac 0xff Connect
0xca 0xff Disconnect
0xaa 0xf1 Toggle dBA/dBC
0xaa 0xf2 Toggle Scale (Auto, 30-80, 50-100, 80-130)
0xaa 0xf3 Toggle Min/Max/Current
0xaa 0xf4 Toggle Fast/Slow
0xaa 0xf5 Toggle Hold
0xaa 0xf6 Toggle Backlight
0xaa 0xf7 Toggle Time/Date
0xaa 0xf8 Power Off
0x7e 0x00 ... Setup Logging (see below)
0xad 0xda Memory Status
0xd3 0xda 0xXX 0xYY Transfer YYXX-th block of data (block length: 256)
0xaa 0xc1 Clear Memory

Measurements and settings

Current settings and measurements are continually streamed over the serial bus, without any prompting from the PC. Data is encapsulated in packets of 13 bytes. The packets are structured as follows:

1 2 3 4 5 6 7 8 9 10 11 12 13
0x7f Measurement Flags/Mode ? Date 0x00


Setup Request

A recording can be setup remotely (which will start instantly or after pressing a button).

1 2 3 4 5 6 7 8 9 10
0x7e ? Interval Date Flags

Status Response

This is the response to the Memory Status (0xad 0xda) command.

1 2 3 4 5 6 7 8 9
0xd1 0x05 0x00 0x01 0xd2 Used memory blocks Length of last block 0x10 or 0x20


Each recording starts with a header:

1 2 3 4 5 6 7 8 9 10 11
0x7f 0xf7 or 0xff 0xff 0x01 0x00 Flags Date

- Flags: 0x0a for dB(A) or 0x0c for dB(C).

- Date. Byte 6: Year; Byte 7: Month; Byte 8: Day; Byte 9: 2 bits unknown, 6 bits for Hour; Byte 10: Minutes; Byte 11: Seconds.