User's Manual

905U-K Radio Telemetry Module User Manual



ELPRO Technologies Pty Ltd 2001 Page 30
occurred for this input within this time, then a transmission is set for this input after the update
time has expired. Each input signal has its own timer - when a transmission occurs for this
input (either a change transmission or an update transmission) the timer is reset to zero. If the
timer reaches the Update Time value, then a update transmission occurs.
Digital inputs (both external inputs and internal) have a separate update time for their "off"
state and "on" state. This allows the input to be reported differently depending on its state. If
the digital input is an alarm, then a user may wish the input to be updated more frequently
when in the alarm state than when not in the alarm state. The analogue input and pulsed
inputs only have one update time value.
Valid values are 10 seconds to 120 hours. If less than 10 seconds is entered, the value will
default to 10 seconds. If zero is entered, then there will be no update transmissions for this
input.
4.3 Digital Inputs
Apart from update times,
the only configurable
parameter for digital inputs
is the paralysis time. This
parameter can be changed
by selecting the Unit details
option.
If a value of zero is entered,
then there is no paralysis
time.
4.4 Analogue Input
There are three parameters which
may be adjusted for the analogue
input.
The
change sensitivity
is the
amount of change since the last
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.