Digital Input And Output Wiring - Siemens 353 User Manual

UM353-1B

7.4.4 Digital Input and Output Wiring

Connections to Digital Input and Digital Input Universal function blocks are shown in Figure 7-11. Wiring for
internal and external power sources is shown. Semiconductor devices can replace the mechanical switches shown.
Wiring guidelines are found in Section 7.4.1.
Digital input commons, e.g. DIN1 (-), are isolated from station common and from case/safety ground.
Model 353
Rear Terminals**
Transmitter
Supply
26 Vdc
24V
External
Supply
Common Ground Bus
* Or any station common terminal
Earth
** See Table 7-1 for DIN3 terminals.
Ground
A. DIN1 and 2
Digital output wiring is shown in Figure 7-12. Three diagrams are provided showing current and voltage outputs.
Note the use of transient suppression diodes in Figure 7-12C. Always install a transient suppression component
across a reactive component, such as a relay coil, to protect the semiconductor devices in the Siemens 353.
Digital output common, DOUTC, is connected to station common.
April 2012
_
+
5
9*
Common
11
(+)
DIN1
12
(-)
13
(+)
DIN2
14
(-)
Figure 7-11 Digital Inputs DIN and DINU
Model 353
Rear Terminals***
Transmitter
Supply
26 Vdc
24V
External
Supply
Common Ground Bus
* Limits current to 6 mA maximum.
Earth
** Or any station common terminal.
Ground
*** See Table 7-1 for DIN3 terminals
B. DINU1 and 2
Installation
_
+
39
40**
Common
Current
35
(+)
Limiter*
DINU1
36
(-)
Current
37
(+)
Limiter*
DINU2
38 (-)
7-13