Installation manual

2–84 Hardware installation
Operation
Receiving commands through the optocoupler inputs
For a pulse–based command (such as “Take”), the MI 3040IO will be triggered on the leading edge of a pulse. The dura-
tion of the pulse can be nearly arbitrary since the falling edge is essentially ignored. However, there is a frequency limit
of 4 Hz; that is, pulses shorter than 125 msec. are not guaranteed to trigger Saturn events; and, each pulse must be fol-
lowed by a silent duration of at least 125 msec.
For a level–based command (such as “GPI/O Disable”), both edges of the signal will trigger the action. A contact closure
on a particular port will turn on the event associated with that port; an open contact will turn off the event. Once again,
no more than four events (i.e., eight signal transitions) can occur in one second.
Reporting status through the relay outputs
For a pulse–based report (such as “Transition Completed”) a “pulse” generated by the MI 3040IO is approximately 1
second long (the pulse may last more than 1 second, but not less). If a second event occurs before the first event’s pulse
has expired, the relay will be pulsed briefly, then remain closed for 1 second after the start of the second event.
For a level–based report (such as “B Bus is on–air”) the MI 3040IO will generate a contact closure to indicate a status
of “ON” and an open contact to indicate “OFF.”