Panasonic FP7 User Manual page 29

 Internal circuit diagram and external connection diagram
5V±10%
12V±10%
24V±10%
Ω
R1=10 k , R2a=4.3 k
①
Voltage detection circuit
 Characteristics of input circuit
• The multi I/O unit has a circuit for detecting an input voltage and switching an input
impedance. See the following table as a guide for input impedances when using each
voltage.
Voltage Input impedance
5 V 1/ {(1/4.3 kΩ) + (1/5.6 kΩ) + (1/510 Ω) } ≒ 420 Ω
12 V 1/ {(1/4.3 kΩ) + (1/5.6 kΩ) } ≒ 2.43 kΩ
24 V
4.3 kΩ
• Input impedances are switched in three stages in the 5-24 V mode, and in two stages in the
12-24 V mode. Input currents vary like the following graphs. The respective minimum ON
voltages and maximum OFF voltages in the 5-24 V mode and 12-24 V mode are different.
(mA)
5V-24V mode
10
8
Min. ON
4.2V
6
4
Max. OFF
2.8V
2
0
0 5 10
5V±10% 12V±10%
X0
Xn
COM
Ω Ω
, R2b=5.6 k , R2c=510
-5℃
25℃
60℃
15 20 25 30
24V±10%
Ω
②
Internal circuit
(mA)
12V-24V mode
10
8
Min. ON
7.5V
6
4
Max. OFF
5.0V
2
0
0
5
(V)
3.1 Input/Output Specifications
R1
R2c
R2b
①
R2a
R1
R2c
R2b
①
R2a
10 15 20
12V±10% 24V±10%
②
-5℃
25℃
60℃
25 30
(V)
3-5