FBVi-2U4-4T |
FBVi Operation
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Resistance Input mode (Passive Input)
P
assive Inputs
are all those devices that vary in resistance, including switch contacts.
Resistance
measurement
Temperature
Measurement
Switch Contact
Pulse counting
24 V AC
Detection
Univers
al Input
n/a
Uniput
These all require a current supplied by the
FLX
terminal so that this resistance can be measured.
The passive sensor types supported by the
FBVi-2U4-4T
are:
•
Pre-programmed Passive Temperature Sensors.
•
Potentiometer (normally used as a 0 to 10 K
Ω
or a 1 K
Ω
to 11 K
Ω
variable resistor to give a 0 to 100 %
output).
•
Volt-Free Digital Input (the controller strategy measures the contact resistance and gives a
0
or
1
output).
•
Straightforward Resistance measurement. This can be used with the
Make Linear
block to give a
temperature output for temperature sensors that are not factory pre-programmed into the
FBVi-2U4-
4T
.
In
CXpro
ᴴᴰ
simply select ‘
Resistance
’ sensor type in the
Point Module
and select
Pulsed
in the
Advanced
parameters (the
Pulsed
option increases accuracy by eliminating any self-heating in the passive
temperature sensor, while the
Continuous
option can trade absolute accuracy for speed).
In
Passive Input Mode
the
Uniputs™
and Universal Inputs configure like this:
Note:
The reference voltage can be pulsed or continuous, using the solid state switch.
A pulsed reference gives optimum accuracy by eliminating self-heating in the sensor, and this is the
default setting.
