©
National Instruments Corp.
13
FP-CTR-500 and cFP-CTR-500
Off Pulse
In Off Pulse mode, the output channel starts high and goes low
when the terminal count is exceeded. The output channel returns to
high after one count. In Figure 10, the terminal count is 4.
Figure 10.
Output of a Channel Set to Off Pulse Mode
Short-Circuit Protection
If the protection circuitry detects a short-circuit condition on an
output channel, it disables the output. If the protection circuitry
disables an output that would otherwise be in the ON state, the
status indicator for that channel remains lit, but the output
transistor is turned off.
Detecting a Short-Circuit Condition
To determine if a channel is in a short-circuit condition, measure
the voltage between the V
OUT
and V
SUP
terminals. If the voltage is
greater than 1 V, the channel is in a short-circuit condition. Correct
the problem and reset the circuit.
Resetting a Channel in a Short-Circuit Condition
To reset a channel in a short-circuit condition, determine the cause
of the condition and disconnect the load from the channel. The
channel resets automatically when the load is removed.
Alternatively, if completely removing the channel load is not
convenient, reset the channel in any of the following ways.
•
In FieldPoint software,write a
0
to the channel. The channel
resets immediately.
•
Disconnect the external power supply from the
[c]FP-CTR-500.
0
1
2
3
4
0
1
2
3
4
0
1
Output
Count
Input
