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Stretched triac output, Comparing stretched triac output to triac output, Usage – Echelon I/O Model Reference for Smart Transceivers and Neuron Chips User Manual

Page 184: Example

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174

Timer/Counter Output Models

Usage

unsigned int

output-value

; // for 8-bit output

unsigned long

output-value

; // for 16-bit output

io_out(

io-object-name

,

output-value

);

Example

IO_1 output pulsewidth clock(7) ioDimmer;

mtimer repeating tick;
unsigned short brightness;

when (...) {
tick = 10; // start clock for fading
brightness = 255; // start brightness for fading
}

when (timer_expires(tick_timer)) {
io_out(ioDimmer, --brightness);
if (brightness == 0) {
tick = 0;
// turn off the timer
}
}

Stretched Triac Output

The stretchedtriac I/O model is used to control the delay of an output pulse signal

with respect to an input trigger signal. For control of AC circuits using a

stretchedtriac I/O object, the sync input is typically a zero-crossing signal, and
the pulse output is the triac trigger signal. The output pulse width is

programmatically controlled, normally active low, but it can be inverted. The

pulse width is independent of the Neuron input clock.

You can use this I/O model to control AC circuits that use a triac device, such as

lamp dimmers.
This model applies to Series 5000 Neuron Processors and Smart Transceivers.

For Series 3100 devices, see

Triac Output

on page 179.

Comparing Stretched Triac Output to Triac Output

Figure 65 on page 175 shows basic triac operation for a Series 3100 device using
the triac I/O object. For a Series 3100 device, the turn-on pulse has a fixed

duration of 25.6 μs, which is sufficient to control many triac devices.