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In i t i a l Co n f i g u r a t i o n
The initial configuration of each port depends on the input/output
jumper setting of each port, on the setting of the jumper JP4, and on
whether the power was actually disconnected or whether the system
was hot reset.
If jumper JP4 is not enabled, all ports configured by software are
automatically set as input ports during system start up or reset, with a
default signal level of logic 1 (high). All ports set via jumpers as
output ports are set as output ports during system start up or reset,
signal level logic 0 (0 V).
If the jumper JP4 is enabled and the initial configuration is caused by a
reset, all ports will return to the states they had just prior to the reset.
The reset must be a "hot" reset (power not disconnected) for enabled
JP4 to return ports to their prior values. Otherwise, the card behaves
as though JP4 were not enabled. Refer to "Jumper settings" in Chapter
2 for more information.
Dr y Co n t ac t Su p p o r t f o r Di g i t al In p u t
Each digital input channel accepts either dry contact or 0 ~ 5 V
contact inputs. Dry contact capability allows the channel to respond
to changes in external circuitry (e.g., the closing of a switch in the
external circuitry) when no voltage is present in the external circuit.
Figure 3-1 shows external circuitry with both wet and dry contact
components, connected as an input source to one of the card's digital
input channels.
External
Int ernal
1.5 K Ω
0.5 W
Resistor
in
Parallel
Figure 3-1: Wet and dry contact inputs
1 6
PCI-1751
User's Manual
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
wet
DC
PC 5 V
10 K Ω
Buffer
Dry Cont act:
Open
High
Close
Low
Wet C ontact : 2. 0~5.25 V
High
D C
0~0.8 V
Low
D C
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