Echelon I/O Model Reference for Smart Transceivers and Neuron Chips - Manual (Page 172)

162 Timer/Counter Output Models
when (...) {
io_out(ioAlarm, 100);
// outputs 3.125kHz signal at clock(3)
}
when (...) {
io_out(ioAlarm, 50);
// outputs 6.25kHz signal at clock(3)
}
when (...) {
io_out(ioAlarm, 0);
// output signal is stopped
}
Infrared Pattern Output
An infrared_pattern I/O model produces a series of timed repeating square wave
output signals. The frequency of the square wave output is controlled by the
application. Normally, this frequency is the modulation frequency used for
infrared transmission.
This I/O model is useful for driving an infrared LED to provide infrared control of
devices that support infrared remote control. For example, for a Series 3100
device with a 10 MHz input clock, a clock(1) configuration and an output-
frequency value of 33 results in a 37.878 kHz (38 kHz) modulation signal.
This model applies to 3120 Power Line Smart Transceivers, 3150 Power Line
Smart Transceivers, 3170 Power Line Smart Transceivers, and Series 5000
Neuron Processors and Smart Transceivers.
Hardware Considerations
The pattern of the modulation frequency is controlled by the application, which
specifies how long the output is active and how long the output is idle. This
pattern is then repeated to produce a sequence of frequency output bursts
separated by idle periods.
Timer/Counter 1
Timer/Counter 2
IO10
IO9
IO8
IO0
IO1
IO2
IO3
IO4
IO5
IO6
IO7
High Current Sink Drivers for 3100 Family Devices
IO11
System Clock
Divide Chain
Figure 61. Infrared Pattern Output