Control Delay

Purpose

The Control Delay performs routine timing and sequencing operations without consuming DSP resources.  It can be used to generate a delayed action, a repetitive action, and when multiple devices are linked together, complex sequences of events can be programmed.

This timer is based on windows timing; consequently, accuracy of timing intervals is limited.  Short delay accuracy is limited to 100 msec and delays from 100 to 3600 seconds are limited to 1-second accuracy.

Controls

Trigger

The trigger button starts the timing sequence.  The sequence begins only once for each cycle of the trigger.  Trigger polarity is used to select the press or release action.

Trigger Polarity

The timer is triggered on a transition of the trigger input.  A complete cycle of the trigger consists of both a “press” and “release” action; thus the trigger polarity is used to select which action triggers the timer.  If the trigger polarity is On, then the Timer is triggered by the “press” action.  If the trigger polarity is Off, the timer is triggered by the release action.

Delay Time

When the timer is triggered, the timer immediately enters the Delay Phase.  The Delay time controls the duration of the Delay Phase.  The range of the control is 0-3600 seconds.

Pulse Time

After the Delay Phase, the timer begins the Pulse Phase.  The length of the Pulse Phase is controlled by the Pulse Time.  The range of the control is 0-3600 seconds.

Delay LED

The Delay LED is active during the Delay Phase of the timer sequence.

Pulse LED

The Pulse LED is active during the Pulse Phase of the timer sequence.

Active LED

The Active LED is active when the Control Delay has been triggered and a timing sequence is in process.  If Loop Enable is set, Active is on continuously.

Retriggerable

In default operation, additional triggers are ignored while a timing sequence is in process.  If Retriggerable is Active, trigger pulses during the Delay Phase cause the timer to reset to the beginning of the Delay Phase.  This allows the timer to be used as a missing pulse detector.  Once the timer enters the Pulse Phase, trigger inputs are again ignored until the sequence is completed.

Reset

Output Reset will terminate any timing sequences that are in process and clear all output LEDs.  If "Loop Enable" is set, the output is reset to the beginning of the Delay Phase and Looping is continued.

Loop Enable

Loop Enable causes the timer to immediately trigger and begin cycling between the Delay and Pulse phases.  This is basically a digital oscillator with a period equal to Delay Time + Pulse Time.  In this condition, the Pulse and Delay LED’s are inverses of each other.  This mode of operation is useful for triggering repetitive operations such as a standard information announcement in an airport.