Echelon I/O Model Reference for Smart Transceivers and Neuron Chips - Manual (Page 39)

I/O Model Reference 29
returned by subsequent calls to io_in( ) until a new value is latched based on the
timing in the hardware.
The period input and ontime input models latch a new value on the falling edge
of the input signal (or if the invert keyword is used, these models latch the new
value on the rising edge of the input signal). The pulsecount input model latches
a new value every 0.8388608 seconds. See the
Neuron C Programmer’s Guide for
more information about timer frequencies and timer accuracy.
Generally, new values written to timer/counter output objects are acted upon at
the end of the current output signal period. Exceptions to this rule are oneshot
output and I/O models that have been disabled (that is, have a zero control
value), all of which take effect upon return from the io_out( ) function.
Output Models
The following timer/counter output models reflect a new output value at the end
of the current output signal period:
• edgedivide output
• frequency output
• pulsewidth output
• stretchedtriac output
• triac output
• triggeredcount output
The following timer/counter output models reflect a new output value upon
return from the io_out( ) function:
• oneshot output
• pulsecount output
All timer/counter output models respond to a zero output value upon return from
the io_out( ) function.