Modbus register addresses for AQT530 - AQT530

AQT530 Configuration Guide
Document code
M212572EN
Revision
E
Language
English
Product
AQT530
Document type
User guide

The following register addresses are available in AQT530. The register addresses are:

  • R = Read only
  • RW = Read/write
  • W = Write only
Once any AQT530 configuration settings are changed through the Modbus interface, new settings must be stored to non-volatile memory by using Modbus register 00FEh, otherwise new configuration will be lost after reboot. See register 00FEh description in Table 1.

For example, in order to change the LPC measurement interval to 2 minutes through Modbus:

  • Write value 2 to register 007Fh
  • Write value 1 to register 00FEh (save changes to non-volatile memory)
Table 1. Modbus register addresses
Address RW Type Unit Register count Description
0000h R int16 ppb 1

Nitrogen dioxide (NO2) concentration in parts per billion (ppb) with linear correction

  • For a value without linear correction, use register 006Ch
  • For µg/m3 value, use register 0066h
0001h R int16 ppb 1

Sulfur dioxide (SO2) concentration in parts per billion (ppb) with linear correction

  • For a value without linear correction, use register 006Dh
  • For µg/m3 value, use register 0067h
0002h R int16 ppb 1

Carbon monoxide (CO) concentration in parts per billion (ppb) with linear correction

  • For a value without linear correction, use register 006Eh
  • For µg/m3 value, use register 0068h
0004h R int16 ppb 1

Hydrogen sulfide (H2S) concentration in parts per billion (ppb) with linear correction

  • For a value without linear correction, use register 0070h
  • For µg/m3 value, use register 0069h
0005h R int16 ppb 1

Trioxygen (ozone) (O3) concentration in parts per billion (ppb) with linear correction

  • For a value without linear correction, use register 0071h
  • For µg/m3 value, use register 006Ah
0006h R int16 ppb 1

Nitric oxide (NO) concentration in parts per billion (ppb) with linear correction

  • For a value without linear correction, use register 0072h
  • For µg/m3 value, use register 006Bh
0008h R int16 0.1 μg/m3 1 Particulate matter PM2.5 with linear correction 1
  • For a value without linear correction, use register 0073h
0009h R int16 0.1 μg/m3 1 Particulate matter PM10 1
  • For a value without linear correction, use register 0074h
000Ah R int16 0.1 °C / 0.1 °F 1

Air temperature (HMP110) in Celsius or Fahrenheit, depending on configuration

Current configuration available from register 001Ch
000Bh R int16 0.1 %RH 1 Air humidity (HMP110)
000Ch R int16 0.1 hPa 1 Air pressure from an on-board analog pressure sensor
0013h R uint16 y 1 Calibration year
0014h R uint16 mo 1 Calibration month
0015h R uint16 d 1 Calibration day
0016h R uint16 - 1 Unit configuration flags (bits/description)
Bits Description
15:2 Reserved
1

LPC configuration:

  • 0 = No LPC
  • 1 = LPC
0 Reserved
001Ah R int16 s 1 Seconds elapsed after last measurement data update
001Bh R int16 - 1 Gas measurement validity
  • 0 = Measurement is not valid
  • 1 = Measurement is valid (includes 24-hour stabilization time after power-up and temperature is within valid range (below 38.0 °C)

Flags can be read separately from registers 0033h and 0034h
001Ch R uint16 - 1 Temperature unit configuration
  • 0 = Celsius (default)
  • 1 = Fahrenheit
001Fh R int16 % 1 Device health index (combined percentage of usage of sensor cells, decreases from 100 %)
  • 100 % = Full health
  • 0 % = All sensors over-aged
0033h R int16 - 1 Gas cell stabilization invalidation flag
  • 0 = 24-h stabilization time after power-up has passed
  • 1 = 24-h stabilization time after power-up not passed and measurement is invalid
0034h R int16 - 1 Gas cell temperature invalidation flag
  • 0 = Cell temperature valid
  • 1 = Cell temperature too high (≥ 38.0 °C) and measurement invalid
0036h R int16 - 1 Humidity compensation (gas compensation)
  • 0 = Humidity compensation disabled
  • 1 = Humidity compensation enabled
0037h R int16 0.1 μg/m3 1

Particulate matter PM1 with linear correction 1

  • For a value without linear correction, use register 0075h
004Bh R int16 - 1

Status reported by device

  • 0 = Unknown. Status information not yet available, starting up
  • 1 = Ok. Operating normally
  • 2 = Degraded. Operating but functionality degraded
  • 3 = Faulty

For more information, see status code from register 004Ch
004Ch R int16 - 1

Status codes

  • 0 = No specific status to report
  • 1 = LPC malfunction
  • 2 = HMP110 malfunction
004Fh R uint16 - 1 AQT base module firmware version major number
0050h R uint16 - 1 AQT base module firmware version minor number
0051h R uint16 - 1 AQT base module firmware version build number
0052h R uint32 - 2 AQT base module firmware version hash number
0054h R uint16 - 1 HMP device firmware version major number
0055h R uint16 - 1 HMP device firmware version minor number
0056h R uint16 - 1 HMP device firmware version revision number
0057h RW uint16 y 1 System time year
  • Read = System time is read into cache when 0057h is read. Other registers return values from cache
  • Write = Register value is written to cache, and system time is updated when 005Ch is written
0058h RW uint16 mo 1 System time month
0059h RW uint16 d 1 System time day
005Ah RW uint16 h 1 System time hours
005Bh RW uint16 min 1 System time minutes
005Ch RW uint16 s 1 System time seconds
0065h RW uint16 - 1

Select the ppb to µg/m3 conversion type for registers 0066h - 006Bh

  • 0 = EU standard (temperature t = +20 °C, pressure p = 1013.25 hPa) (default)
  • 1 = International standard (WHO, temperature t = +25 °C, pressure p = 1013.25 hPa)
  • 2 = Temperature based dynamic (ambient temperature from HMP110, pressure p = 1013.25 hPa)
0066h R int16 0.1 µg/m3 1

Nitrogen dioxide (NO2) concentration calculated from ppb value with linear correction (register 0000h)

Calculated by means of selected conversion type . Calculation method is selected with register 0065h
0067h R int16 0.1 µg/m3 1

Sulfur dioxide (SO2) concentration calculated from ppb value with linear correction (register 0001)h

Calculated by means of selected conversion type . Calculation method is selected with register 0065h
0068h R int16 1 µg/m3 1

Carbon monoxide (CO) concentration calculated from ppb value with linear correction (register 0002h)

Calculated by means of selected conversion type. Calculation method is selected with register 0065h
0069h R int16 0.1 µg/m3 1

Hydrogen sulfide (H2S) concentration calculated from ppb value with linear correction (register 0003h)

Calculated by means of selected conversion type. Calculation method is selected with register 0065h
006Ah R int16 0.1 µg/m3 1

Trioxygen (ozone) (O3) concentration calculated from ppb value with linear correction (register 0005h)

Calculated by means of selected conversion type. Calculation method is selected with register 0065h
006Bh R int16 0.1 µg/m3 1

Nitric oxide (NO) concentration calculated from ppb value with linear correction (register 0006h)

Calculated by means of selected conversion type. Calculation method is selected with register 0065h
006Ch R int16 ppb 1 Nitrogen dioxide (NO2) concentration in parts per billion (ppb), without linear correction
  • For a value with linear correction, use register 0000h
006Dh R int16 ppb 1 Sulfur dioxide (SO2) concentration in parts per billion (ppb), without linear correction
  • For a value with linear correction, use register 0001h
006Eh R int16 ppb 1 Carbon monoxide (CO) concentration in parts per billion (ppb), without linear correction
  • For a value with linear correction, use register 0002h
0070h R int16 ppb 1 Hydrogen sulfide (H2S) concentration in parts per billion (ppb), without linear correction
  • For a value with linear correction, use register 0004h
0071h R int16 ppb 1 Trioxygen (ozone) (O3) concentration in parts per billion (ppb), without linear correction
  • For a value with linear correction, use register 0005h
0072h R int16 ppb 1 Nitric oxide (NO) concentration in parts per billion (ppb), without linear correction
  • For a value with linear correction, use register 0006h
0073h R int16 0.1 μg/m3 1 Particulate matter PM2.5, without linear correction 1
  • For a value with linear correction, use register 0008h
0074h R int16 0.1 μg/m3 1 Particulate matter PM10, without linear correction 1
  • For a value with linear correction, use register 0009h
0075h R int16 0.1 μg/m3 1 Particulate matter PM1, without linear correction 1
  • For a value without linear correction, use register 0037h
0076h R int16 - 1 LPC data state
  • 0 = LPC data not ready
  • 1 = LPC data ready
007Bh R int16 - 1 LPC humidity invalidation flag

Combines all PM values from registers 007Ch - 007Eh

  • 0 = LPC humidity ok
  • 1 = LPC measurement may be invalid due to high humidity
007Ch R int16 - 1 LPC humidity invalidation flag for PM1 value
  • 0 = LPC humidity is ok
  • 1 = LPC PM1 measurement may be invalid due to high humidity
007Dh R int16 - 1 LPC humidity invalidation flag for PM2.5 value
  • 0 = LPC humidity is ok
  • 1 = LPC PM2.5 measurement may be invalid due to high humidity
007Eh R int16 - 1 LPC humidity invalidation flag for PM10 value
  • 0 = LPC humidity is ok
  • 1 = LPC PM10 measurement may be invalid due to high humidity
007Fh RW int16 min 1

LPC measurement interval in minutes (2 - 255)

Default: 10 minutes
0086h RW int16 % 1 CO linear correction gain value (1 ... 255, corresponding gain values 0.01 ... 2.55)
0087h RW int16 % 1 O3 linear correction gain value (1 ... 255, corresponding gain values 0.01 ... 2.55)
0088h RW int16 % 1 NO2 linear correction gain value (1 ... 255, corresponding gain values 0.01 ... 2.55)
0089h RW int16 % 1 SO2 linear correction gain value (1 ... 255, corresponding gain values 0.01 ... 2.55)
008Ah RW int16 % 1 NO linear correction gain value (1 ... 255, corresponding gain values 0.01 ... 2.55)
008Bh RW int16 % 1 H2S linear correction gain value (1 ... 255, corresponding gain values 0.01 ... 2.55)
008Ch RW int16 ppb 1 CO linear correction offset

−10000 ... 10000
008Dh RW int16 ppb 1 O3 linear correction offset

−10000 ... 10000
008Eh RW int16 ppb 1 NO2 linear correction offset

−10000 ... 10000
008Fh RW int16 ppb 1 SO2 linear correction offset

−10000 ... 10000
0090h RW int16 ppb 1 NO linear correction offset

−10000 ... 10000
0091h RW int16 ppb 1 H2S linear correction offset

−10000 ... 10000
0092h RW int16 ‰ 1

PM2.5 linear correction gain value (per mille)

Valid range: 1 ... 10000 (0.001 ... 10.000)
0093h RW int16 ‰ 1

PM10 linear correction gain value (per mille)

Valid range: 1 ... 10000 (0.001 ... 10.000)
0094h RW int16 0.1 µg/m3 1

PM2.5 linear correction offset

Valid range: -10000 ... 10000 (-1000.0 ... 1000.0)
0095h RW int16 0.1 µg/m3 1

PM10 linear correction offset

Valid range: -10000 ... 10000 (-1000.0 ... 1000.0)
0096h RW int16 ‰ 1

PM1 linear correction gain value (per mille)

Valid range: 1 ... 10000 (0.001 ... 10.000)
0097h RW int16 0.1 µg/m3 1

PM1 linear correction offset

Valid range: -10000 ... 10000 (-1000.0 ... 1000.0)
0098h R uint32 s 2 Device uptime in seconds from last power-up
00B4h R char[8] - 4 AQT product device serial number (8-character string)
00B8h R char[8] - 4 HMP serial number (8-character string)
00BCh R char[8] - 4 LPC serial number (8-character string)
00C3h R int16 - 1 Circuit board serial number, part 1
00C4h R int16 - 1 Circuit board serial number, part 2
00C5h R int16 - 1 Circuit board serial number, part 3
00F4h R uint16 - 1 LPC firmware version major number
00F5h R uint16 - 1 LPC firmware version minor number
00F6h R uint16 - 1 LPC firmware version build number
00F7h R uint32 - 2 LPC firmware version hash number
00FAh W uint16 - 1 Reset device
  • 1 = Reset device
  • Other values = no effect
00FEh W uint16 - 1 Write configuration to the onboard non-volatile memory
  • 1 = Write configuration
  • Other values = no effect
1

When PM concentrations reach the upper measurement limit of the laser particle counter (LPC) due to some exceptional event, the PM readings may temporarily be negative and the LPC reboots itself. For example, the unloading of sand in a nearby construction site and the resulting sand dust may cause the particle concentration to be temporarily drastically different from normal. Because of this AQT530 initially shows very high PM readings and then negative readings. AQT530 typically recovers from these exceptional events back to normal operation.