©
National Instruments Corp.
5
FP-CTR-500 and cFP-CTR-500
Inputs
Each input channel has one input terminal, V
IN
. Each channel also
has V
SUP
and COM terminals that can supply power to field
devices. You can connect the eight count-input channels and four
gate-input channels to devices with sourcing outputs. The
[c]FP-CTR-500 has
sinking
inputs, which means that the V
IN
terminal provides a path to common.
The [c]FP-CTR-500 input channels are optically isolated from the
rest of the FieldPoint bank and have current-limiting circuitry. All
the input channels are referenced to the C and COM terminals.
When the voltage across V
IN
and COM is 10 V or greater, current
flows through V
IN
and turns on the optoisolator, registering in an
ON state for the channel. When the voltage across V
IN
and COM
is 6 V or lower, current does not flow through V
IN
and the channel
is in the OFF state.
Ensure that the sourcing-output devices have OFF state leakage
currents of less than 0.2 mA so they do not generate false ON state
readings.
Outputs
Output 0
13
29
30
Output 1
14
29
30
Output 2
15
31
32
Output 3
16
31
32
1
Install a 1 A maximum, fast-acting fuse on each V
OUT
terminal.
2
Install a 2 A maximum, fast-acting fuse on each V and V
SUP
terminal.
Table 1.
Terminal Assignments (Continued)
Channel Name
Terminal Numbers
V
IN
or V
OUT
1
V
SUP
2
COM