Vaisala AQT400, User Manual

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7. Data Formats
7.1. Data Format in ASCII Mode
To use the RS-485 port in ASCII mode, set parameter rs485_mode to 0 .
In ASCII mode, the device prints CSV formatted measurements based on measint
parameter. The measurement interval can be 1 ... 1440 minutes.
Table 3 CSV Output Format
Field Description Example
DATE
Date and time in ISO8601 format 2015-07-01T12:34:56
TEMP
Air temperature in ºC or ºF (
tempunit
parameter) 23.5
HUM
Air humidity in %RH 43.2
PRES
Air pressure in mbar 1013.4
MEAS
Gas measuremets in ppm
Particle measurements in μg/m
³
0.023,0.067,26.2,105.7
CONF
Specifies the printing order of the measurements in
the MEAS field
Always includes T:H:P (temperature, humidity, and
pressure).
T:H:P:NO2:SO2:PM2.5:PM10
UPTIME
Device uptime in seconds
Measurements are considered valid when uptime is
more than 86400 seconds (one day).
131422
7.2. Data Format in Modbus Mode
To use the RS-485 port in Modbus mode, set parameter rs485_mode to 1 . The device
complies with Modbus ASCII standard, but does not support Modbus RTU mode. For full
specifications, see
http://www.modbus.org/ .
AQT400 supports the following Modbus function codes:
Table 4 Modbus Function Codes
Command Function Code Description
regread
0x03 Reads holding registers
Chapter 7 – Data Formats
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