Input Circuit Configuration And External Connection - Fuji Electric MICREX-SX series SPF User Manual

Section 3 Specifications

(2) Input circuit configuration and external connection

The 24V DC digital input circuits are available for high, medium and low speed. They all have the similar circuit structures but
with different response speeds. When making the connection of external digital input devices, the one ends of all input devices
(e.g. buttons and switches) are connected together and called the external common wire, while the other ends of input circuits
are connected to the input terminals X0, X1, X2, etc., of SPF. Then finish it by connecting the external common wiring and
internal common terminal S/S to the 24VDC power. When connecting the internal common terminal S/S to 24V+ (positive) and
the external common wire to 24V- (negative), then the circuit serves as a sink input. On the contrary, while exchange the wiring
of the above internal and external common will serve as a source input. The above wiring schemes can illustrated below:
• Wiring of source input
External
power 24V DC
supply
+24V
SPF
24V DC
(Not available when using
an expansion unit without
power supply.)
• Wiring of sink input
External
power
24V DC
supply
+24V
SPF
24V DC
(Not available when using
an expansion unit without
power supply.)
External common line
NPN
sensor
- S/S X0
Internal
common
terminal
R2
X0
External common line
PNP
sensor
-
S/S X0
Internal
R1
common
terminal
R2
X0
X1 X2 X3
R1
R1 R1 R1
R2
R2 R2
X1 X2 X3
X3
X1 X2
R1
R1 R1
R2 R2
R2
X3
X1 X2
3-6
Input device
Input circuit