Panasonic FP-M Hardware Manual page 61

Wiring a two-wire type sensor
• If the input of the FP-M is not turned OFF because of
leakage current from the sensor, the use of a bleeder
resistor is recommended, as shown below.
Sensor
Internal
circuit
R: Bleeder resistor (kΩ)
I
: Sensor's leakage current (mA)
The OFF voltage of the FP-M input is 2.4 V, therefore,
select an R value so that the voltage between the COM
terminal and the input terminal will be less than 2.4 V.
• Control board (input impedance is 4.8 kΩ)
The bleeder resistor R is: R
• Expansion board (input impedance is 4.4 kΩ)
The bleeder resistor R is: R
• The wattage W of the resistor is:
(Power supply voltage)
W=
In the actual selection, use a value that is 3 to 5 times
the value of W.
Wiring a LED-equipped reed switch
• When a LED is connected serially to an input
contact such as the LED-equipped reed switch,
make the voltage applied to the FP-M input circuit
greater than 20 V. In particular, take care when
connecting a number of switches in serial.
LED-equipped
reed switch
Input
terminal
FP-M
Bleeder
R C32T
resistor
type
COM
11.52
4.8 I -2.4
10.56
I
4.4 -2.4
2
R
Input
terminal
20 V DC
FP-M
or more
COM
Wiring a LED-equipped limit switch
• If the input of the FP-M is not turned OFF or if the
LED of the limit switch is kept ON because of the
leakage current, the use of a bleeder resistor is
recommended, as shown below.
LED-equipped
limit switch
r
r: Internal resistor of limit switch (kΩ)
R: Bleeder resistor (kΩ)
The OFF voltage of the FP-M input is 2.4 V, therefore
when the power supply voltage is 24 V, select R so that
the current will be greater than I =
• Control board (input impedance is 4.8 kΩ)
The bleeder resistor R is: R
• Expansion board (input impedance is 4.4 kΩ)
The bleeder resistor R is: R
• The wattage W of the resistor is:
(Power supply voltage)
W=
Select a value that is 3 to 5 times the value of W.
Connecting an input device with a
different voltage (ex.: a 5 V sensor, etc.)
• When connecting a device with a power supply
voltage different from the FP-M input voltage, such
as a 5 V sensor, connect in common to the built-in
DC power output terminal as shown below.
Note:
• Some sensors do not allow for this type of use,
therefore check the specifications of the sensor
before wiring.
19
20
Vcc
Built-in DC
power output
terminal
Sensor (5 V DC type)
4-3. Wiring
Input
terminal
FP-M
Bleeder
C32T
R
resistor type
COM
24 - 2.4
r
11.52
I
4.8 -2.4
10.56
I
4.4 -2.4
2
R
+
Input
–
0 V
1
2
53