Control Techniques Epsilon EP-P, Reference Manual

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Epsilon EP-P Drive Reference Manual
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Revision A4 www.controltechniques.com
Figure 75: Watchdog Timer - Timing Diagram
One Shot
With this type of timer, when the Input activates, the internal clock begins to count. Once the Preset time is reached, the
Output of the timer turns ON. If the Input of the timer turns OFF before the Output turns ON, then the internal clock keeps
counting and the Output will turn on when Preset time is reached. If the Output is active and a rising edge of the Input timer is
received the Output will be reset. The Output will activate once the Preset time has past.
In the case of the One Shot type timer, once the rising-edge occurs on the Input, it does not matter what happens to the state
of the Input after that during the Preset time. When past the Preset time and the Output is still active and a rising-edge occurs
on the Input the timer will reset. The Output deactivates and will not become active until the Preset time has past.
Figure 76: One Shot Timer - Timing Diagram
Timer Timebase
This parameter is used to select the desired Timebase for each timer object. If you want to control the Timer using actual time
(seconds, or milliseconds, or microseconds) then the Timebase should be set to Realtime. Realtime is the default setting for
the Timebase of each Timer object. When using Realtime, the Preset value of the Timer is entered in units of seconds. For
example, after a program has run, you wish to hold an output active for ten seconds. This is an example that uses Realtime.
However, if you wanted to hold that same output active for ten revolutions of the Master Encoder instead of ten seconds, you
set the Timebase to Synchronized. This means that you are using the master encoder position to control the duration of the
Timer rather than actual Time. When the Timebase of the Timer is set to Synchronized, the Preset is entered in units of Master
Preset
Input
Output
Preset Preset
Active