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Functional description
Two electronic control units are installed in the ESO 99 S controller housing.
The frost controller (SRR) is used to detect the ambient conditions and the heating controller (ELTC-21) is used as a surface thermo-
stat with remote sensor for detecting the heating temperature. Cable glands and terminals are installed for the electrical connection.
SRR frost controller function (device 1)
The SRR frost controller detects the ambient temperature and also detects any frost, snow or ice build-up on the antenna surface.
PT100 sensors are used to detect the ambient temperature. The limit value is factory set to a fixed +4°C. Frost and potential ice build-
up are only expected at temperatures above this value. The coat forming on the monitored surface is registered using a 2-rod probe. A
window function in the SRR 200 enables the parameters to differentiate between water and ice to be set.
These parameters are determined once and cannot be changed without the corresponding software.
If both conditions are met (temperature below +4°C and ice build-up detected), the heating controller is enabled by a potential-free
switching relay in the SRR 200 and heating of the antenna surface begins. As soon as one of the two conditions is no longer met,
the post heating time begins (the time is adjustable using potentiometers on the front panel of the SRR). The heating process is only
ended when the post heating time has elapsed. If the conditions are met again during the post heating time, the post heating time is
(automatically) reset and the control process starts again.
The heating controller keeps the antenna temperature at the set limit value (factory s40 °C). A control input allows the heating
controller to be enabled manually.
The USB port is used for communication with a computer. The frost controller can be set using the SRR 200 Config Tool parameter
setting software. Monitoring is also possible. The instructions for using this software can be found in the “SRR 200 Config Tool” oper-
ating manual.
