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48
PAM1 MK2
User Handbook Issue 1
2.22
GPI Connectivity
The GPI operation is described pictorially by the pin out diagram shown below.
In
Momentary Mode
,
Dim
and
Cut
GPI's
latch in a toggle manner, i.e. one closure to
ground toggles the function ON: the next
ground toggles it OFF. In an ON state: the
GPI pin is driven low to allow an LED to be
fed from the port. This LED drive is briefly
pulsed high at about 100Hz to allow the port
to be read whilst it is driving.
The preset recall GPI’s in
‘Latching’
mode
are mutually exclusive.
!
Note that the +5V power from this
connector is intended to drive a "1-of-N"
LED.
If multiple LED’s are to be used
simultaneously, then a small external supply
will be needed. An internal resistor within the
PAM1 prevents the +5V rail from being
shorted but limits the current available.
