84
Hold Time
Enter the amount of time needed to hold the sensor reading after the event
has finished, in order for the wash solution to be replaced by process
solution.
5.3.17
Relay or Control Outputs, Spike Control Mode
Basic Timer Operation
This algorithm is typically used to provide a baseline amount of chlorine for disinfection, and periodically shocking
the system with a larger dose. During normal operation, the relay will be reacting to the sensor to maintain a set point
within a programmable Deadband, as described in On/Off Control Mode above. When a Spike event triggers, the
algorithm will change from the normal set point to the Spike Set Point, for the programmed time. Once the time
expires, control to the normal set point resumes. The Onset Time setting allows the user to decide if the programmed
spike duration time starts counting down immediately, or if the controller will wait until the higher set point is
achieved
(or the onset time expires, whichever comes first) before starting the spike Duration timer.
Special Condition Handling
Overlapping timer events
If a second timer event occurs while the first one is still active, the second event will be ignored. An Event Skipped
alarm will be set.
Interlock Conditions
Interlocks override the relay control, but do not change the operation of the timer control.
A digital input or output interlock condition does not delay the relay activation. The relay activation duration timer
will continue even if the relay is deactivated due to an interlock condition. This will prevent delayed events which
can potentially cause problems in they do not occur at the correct time.
“Activate With” Conditions
“Activate with channels” settings override the relay control, but do not change the operation of the timer control.
The relay activation duration timer continues counting when the timer relay is forced on, and ends at the expected
time (event start time plus duration). If the “activate with” condition continues after the end of the event time, the
relay remains activated.
Alarms
An Event Skipped alarm is set when a second timer event occurs while one event is still running.
An Event Skipped alarm is also set when the timer relay never turns on during an event because of an interlock
condition.
The alarm is cleared when the relay is next activated for any reason (the next timer event or HAND mode or “acti-
vate with” force on condition).
Output Details
The details for this type of output include the relay on/off state, HOA mode or Interlock status, accumulated on-
time, current cycle on time, relay type and alarms. The current week number and day of the week is displayed
(even if there is no multi-week repetition event programmed). Cycle Time shows the time counting down of the
currently active part of the cycle.
Settings
Press the Edit key view or change the settings related to the relay.
Set point
Enter the sensor process value at which the relay will activate.
Spike Set point
Enter the sensor process value at which the relay will activate during the Spike
Event time.
Deadband
Enter the sensor process value away from the set point at which the relay will
deactivate. The same Deadband is used for the normal Set Point and the Spike Set
Point.
