Westermo RM-505U-2-E - Manual (Page 34)

505U Radio Telemetry Module
Page 34 © September 2002
transmission which will trigger another transmission for this input. For example, if the last transmitted
value of the input was 55.0%, and the sensitivity is 1.2%, then another transmission will occur if the
measured input value is less than 53.8% or more than 56.2%. If change messages are not required,
then a sensitivity of 100% should be selected.
Each 1% corresponds to 0.2mA of signal. The sensitivity should be set to be greater than the
natural "signal noise" of the analogue input. For example, if there is a signal oscillation of 1% on the
input, then a sensitivity of less than 1% will result in continuous change transmissions which could
overload the radio channel.
The sample time is the time
period for each analogue
input measurement. Between
measurements, the 505U will
operate in "sleep" mode.
When the sample time has
expired, the 505U will turn on
the analogue loop power
supply. After a further time,
called the warmup time, the
505U will make a
measurement of the input.
The warmup time allows the
transducer to stabilise and become accurate after the loop supply is turned on.
The sample time may be entered in minutes, between 1 and 30 000 minutes. If a zero value is
entered, then the loop power supply will be always on. The warmup time may be entered in
seconds between 1 and 127 seconds. If a zero value is entered, then an analogue measurement will
be made as soon as the loop supply is turned on. If both the sample time and warmup time are set
to zero, then an analogue measurement will be taken on every 505U cycle (every 0.5 sec).
4.5 Analog Setpoints
A high setpoint value and a low setpoint value may be entered. The internal setpoint status is
determined by these values in comparison to the analogue input value. If the analogue input is less
than the low setpoint, then the setpoint status is "on". If the analogue input is more than the high
setpoint, then the setpoint status is "off". When the input is between the low and high setpoints, then
the setpoint status remains unchanged.