II - DCE FEL ČVUT v Praze

SIMATIC S7 Ex Analog Modules
Wiring diagram
3-64
SM 33 1
AI 4 x 0/4...20 mA
Input 0
Input 1
Input 2
Input 3
X 2
3 4
331-7RD00-0AB0
x
SF
F0
F1
[EEx ib] IIC
F2
F3
Fig. 3-17 shows the terminal diagram of the analog input module SM 331;
AI 4 x 0/4...20 mA. You will find detailed technical specifications for the
analog input module SM 331; AI 4 x 0/4...20 mA on the following pages.
Logic and
backplane
bus
interfacing
5V internal
ADU
M internal
SF
F (0..3)
Isolation
L +
M
Isolation
390
Isolation amplifier
SF group fault indication [red]
F (0...3) channel-specific fault indication [red]
Fig. 3-17 Module view and block diagram of SM 331; AI 4 x 0/4...20 mA
Notes on
intrinsically-safe
installation
Power supply for a
intrinsically-safe
structure
L +
M
L +
M
L +
M
L +
M
50
50
50
50
L+
M
+
+
+
+
2-wire transducer
4-wire transducer
2-wire
2-wire
2-wire
2-wire
+
–
+
–
+
–
+
–
4-wire
4-wire
4-wire
4-wire
L +
L 0 +
M 0+
M 0-
CH0
L1 +
M1+ CH1
M1- L2 +
M2 +
M2 -
L3 +
M3 +
M3 CH2
CH3
You must connect the DM 370 dummy module between the CPU or IM 153-2
(in a distributed configuration) and the Ex I/O modules whose signal cables
lead into the hazardous location. In a distributed configuration with an active
backplane bus, you should use the ex dividing panel/ ex barrier instead of the
dummy module. Additional information on system design can be found in
Sections 1.3 - 1.5.
In order to maintain the dearances and creepage distances, L+ / M must be
routed via the line chamber LK393 when operating I/O modules with signal
cables that lead to the hazardous location, see Section 1.2.
I/O Modules with Intrinsically-Safe Signals
C79000-G7076-C152-04
M