Lufft ARS31-UMB, Руководство пользователя

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ARS31(Pro)-UMB Operating Manual V9/03.2017
G. Lufft Mess- und Regeltechnik GmbH, Fellbach, Germany 9
Measurements are polled and transmitted over an RS485 interface.
The device is connected using a 4-core cable.
Windows PC software is available for configuration and measurement polling during
commissioning.
4.2 Additional features of ARS31Pro-UMB
In addition, ARS31Pro-UMB determines the threat of icing as follows: for a dry road
– by
cooling to an adjustable temperature value (∆ T1); for a wet road - by comparing the
measured freezing temperature with the road surface temperature while taking account of
the set temperature value (∆ T2).If a threat of icing is determined using one of the methods
described above, the sensor transmits “threat of icing”.“Threat of icing” is only transmitted
as a result of a direct measurement if the road temperature is less than +2°C.
This function must be activated in Configuration of the sensor.
To avoid measurement gaps due to interference during measurement, the sensor is
equipped with an intelligent “hold measurement” function also for threat of icing.
If the cond
ition “threat of icing” was triggered by the freezing temperature measurement
and the freezing temperature enters the hold state, the condition “threat of icing” is also
updated via the last determined freezing temperature and the current road temperature. In
this case, updating of the threat of icing ends simultaneously with the updating of freezing
temperature. However, if during updating the threat of icing is actively determined by
means of a direct measurement, this condition is retained for the set period.
With external sensor the road surface temperature is determined exactly.
4.3 Availability of measurement values
After a successful measurement, the measurement values are available for query until new
measurement values are available. Synchronization between query and measurement
cycle is not needed. It is recommended to poll the sensor every minute. Within the
measurement interval the measured values are immediately updated when they become
available. Due to different environmental conditions the timing of the availability of
measurements can alter in the measurement interval, the measurement values are
therefore not necessarily updated in the grid of the selected measurement interval.
Start measurement Start measurement Start measurement Start
TG 1
availa
ble TG 2 available TG 3
availa
ble
0
min 5
min 10
min 15
min 20
min 25
min 30
min 35
min 40
min 45
min 50
min 55
min 60
min
Figure 2: Example: Measurement interval 20 minutes
1) At time 15 min TG 1 is available and will be issued
2) In the next measurement cycle, at the time 25 min GT 2 is determined and issued. So
TG1 was issued for 10 minutes.
3) In the next measurement cycle, at the time 25 min GT 3 determined and issued. So TG2
was issued for 30 minutes.