Precision Digital PD941 - Manual (Page 33)

ConsoliDator Multi-Channel Controller Instruction Manual
33
High or Low Pulse Alarm
Modes
Pulse Modes are used to generate
an on/off continuous pulsing signal.
Select [HIGH: Pulse Mode] from
Alarm Mode options to continuously
pulse relay when high set point is
reached. Pulsing stops when low
reset point is reached.
Select [LOW: Pulse Mode] from
Alarm Mode options to continuously
pulse relay when low set point is
reached. Pulsing stops when high
reset point is reached.
High Value Enter high process variable set/reset point.
Low Value Enter low process variable set/reset point.
Delay ON Enter a delay between when the set point is reached and the pulse
signal starts.
Delay OFF Enter a delay between when the reset point is reached and the
pulse signal stops.
Pl. Width Enter pulse duration (Energized relay.)
Pl. Delay Enter duration between pulses (De-energized relay.)
Over Enter override menu to override the channel alarm settings.
Pulse Width Pulse Delay Delay ON
Set Point Reached
Figure 20. Pulse Relay Timing Diagram
Example Pulse Mode Scenario
The unit is set to the following:
Alarm Mode: [HIGH: Pulse Mode]
High Value: [16 mA]
Low Value: [10 mA]
Delay ON: [2 sec]
Delay OFF: [3 sec]
Pl. Width: [1 sec]
Pl. Delay: [2.5 sec]
The following describes operation based on the above settings:
The process reaches 16 mA: 2 seconds pass with no relay action.
Relay begins pulsing: on for 1 second, off for 2.5 seconds. ON-OFF alternation continues while the
process is above 10 mA. The process reaches 10 mA: Pulse sequence continues for 3 seconds and
then stops completely until 16 mA is reached again.