Philips INCA 320 - Manual (Page 9)

is configured as a non-inverting output the output is zero
and stays zero and awaits control by the software.
If the output is configured as an inverting output than
during the start-up sequence the output equals the value of
the power supply. This situation stays that way until the
software has taken over the control. In case a flash unit is
switched to the on position with a positive input, the flash
unit will flash or lit continuously.
2.3.2.1 Using the Trigger Input
The trigger input is optically isolated that is different from
the digital I/O as described in 2.3.3.
The following diagram shows an example of how to use
the optical Isolated input.
24V
Inca
p
n
2K7
Figure 2-4 Optical isolated trigger input
When the diode is conducting and thus emitting light, the
software will interpret this as a binary ‘1’.
The input is TTL level compatible.
• input current 6.3 mA < Ion < 10 mA
• Pmax 20 mW
2.3.2.2 Using the Flash and Watchdog
Outputs
The flash and watchdog outputs are optically isolated that
are different from the digital I/O as described in 2.3.3.
The following diagram shows an example of how to use
the optical output.
24V
2K7
Inca
p
n
Figure 2-5: Optical isolated flash and watchdog outputs
When the flash output is defined as active high and the
software sets the flash as active, then the state of the
output is Ioff, and the transistor will not be conducting.
When the flash output is defined as active low, and the
software sets the flash as active, then the state of the
output is Ion, and the transistor will be conducting.
The watchdog will behave the same as the flash output in
the active high definition. More information about the
watchdog can be found in 2.3.4.3.
2005-12-12 Page 7