User's Manual

905U-K.MAN Rev. 1.1 January 2002
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ELPRO Technologies Pty Ltd Page 31
The
sample time
is the time
period for each analogue
input measurement.
Between measurements, the
905U-K will operate in
"sleep" mode. When the
sample time has expired,
the 905U-K will turn on the
analogue loop power
supply. After a further
time, called the
warmup
time
, the 905U-K 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 905U-
K 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.
The setpoint values may
be set between 0 and
100% corresponding to
0mA and 20mA. The low
setpoint may be set to the same value as the high setpoint, however the low setpoint should
not be set to a higher value than the high setpoint.
4.6 Pulse Inputs
There are several configurable parameters for pulse inputs. The debounce value can be
adjusted from the Unit Details selection, as per Digital Inputs.
If either pulse input has an input rate of more than 10Hz, then the Fast Pulse Input option
should be selected from the Pulsed Inputs selection.