21
For communication with device which measure more than one value, there is necessary to add at
the end of command, number of communication channel, where the measured value is mapped.
Command for value reading is
#AAx(CRC) CR
, where
AA
is device address and
x
is number of
communication channel by next table:
Measured value
Number of communication channel
temperature
0
relative humidity
1
computed value
2
barometric pressure (CO
2
concentration)
3
status word (described below)*
4
Relay1 status [0/1]
5
Relay2 status [0/1]
6
* Status word: 16b value return, bite description:
Bit0
0/1
jumper open/closed
Bit1
-
unused
Bit2
0
always 0
Bit3
0/1
Relay1 open/closed
Bit4
0/1
Relay2 open/closed
Bit5
0/1
internal acoustic alarm status
Bit6 -15 -
unused
7. Error States of the device
Device continuously checks its state during operation. In case error is found LCD displays
corresponding error code:
Error 0
- first line of LCD displays „Err0“. Check sum error of stored setting inside device’s
memory. This error appears if incorrect writing procedure to device’s memory occurred or if
damage of calibration data appeared. At this state device does not measure and calculate values. It
is a serious error, contact distributor of the device to fix.
Error 1 -
measured or calculated value (except concentration of CO
2
) is over upper limit of allowed
full scale range. There is a reading „Err1“ on LCD display. Value read from the device is +999.9.
This state appears in case of:
Measured temperature is higher than approximately 600°C (i.e. high non-measurable resistance
of temperature sensor, probably opened circuit).
Relative humidity is higher than 100%, i.e. damaged humidity sensor, or humidity calculation
of humidity is not possible (due to error during temperature measurement).
Computed value – calculation of the value is not possible (error during measurement of
temperature or relative humidity or value is over range).
The value of CO
2
concentration 9999 ppm is correct value!
Error 2 -
there is a reading „Err2“ on LCD display. Measured or calculated value is below lower
limit of allowed full scale range or CO
2
concentration measurement error occurred. Value read
from the device is -999.9. This state appears in case of:
Measured temperature is lower than approximately -210°C (i.e. low resistance of temperature
sensor, probably short circuit).
Relative humidity is lower than 0%, i.e. damaged sensor for measurement of relative humidity,
or calculation of humidity is not possible (due to error during temperature measurement).