Helios Large Display Dual Analog Input Rate/Totalizer Instruction Manual
PD2-6262
40
Relay Sampling Operation
When the signal crosses the set point, the relay trips and the sample time starts. After the sample time
has elapsed, the relay resets. The cycle repeats every time the set point is crossed, going up for high
alarms and going down for low alarms.
The sample time can be programmed between 0.1 and 5999.9 seconds.
Signal Loss or Loop Break Relay
Operation
The following graph shows the loop break relay
operation for a high alarm relay.
When the meter detects a break in the 4-20 mA
loop, the relay will go to one of the following
selected actions:
1. Turn
On
(Go to alarm condition)
2. Turn
Off
(Go to non-alarm condition)
3. Ignore (Processed as a low signal
condition)
Time Delay Operation
The following graphs show the operation of the
time delay function.
When the signal crosses the set point, the
On
time
delay timer starts and the relay trips when the time
delay has elapsed. If the signal drops below the
set point (high alarm) before the time delay has
elapsed, the
On
time delay timer resets and the
relay does not change state. The same principle
applies to the
Off
time delay.
Note: If “Automatic or Manual (
A-mAn
)” reset
mode is selected, the LED follows the reset
point and not the relay state when the relay
is acknowledged.
Set
Reset
Relay
LED
Input
Sample
Time
Sample
Time
Sample
Time
Relay
LED
Input
Loop Break = Ignore
de-energized
energized
off
on
Relay
LED
Loop Break = Off
Relay
LED
Loop Break = On
Set
Reset
