Siemens 6DR2410, Manual

Page: 112 / 276

2 Installation
2.2 Electrical Connection
Manual
110
SIPART DR24 6DR2410
C79000-G7476-C153-03
D
Connection of the serial interface
For V.28 point--to--point connections of the SES, a 9--pin socket strip for round cables in sol-
der technique is available.
7
4
D39
9 pin
External system
V. 28 point-to-point
≤
10 m
6DR2803-8C
SIPART DR19/21/22/24
Serial
interface
Figure 2-2 Connector plug serial interface
9--pin D--plug for round cables (screw terminal C73451-A347-D39
Recommended cable:
4--core unscreened round cable
JE-LiYY 4x1x0.5 BdSi
D
Zero volt system
The SIPART DR24 controllers only have a 0V conductor (ground, GND) on the process side
which is output double at terminals 1/1 and 1/2 of the standard controller. If these GND con-
nections are not sufficient, additional proprietary terminals can be snapped onto the DIN rail
on the power pack. The controller uses a common reference for both inputs and outputs, all
process signals are referred to this point.
The reference line is also connected to vacant module terminals. These may only be used if
practically no input current flows through this connection (see for example figure 2-14, page
116, I 4L).
The power supply connection is electrically isolated from the process signals. In systems
with unmeshed control circuits, the controllers need not be interconnected. In meshed con-
trol loops the GND connections of all controllers must be fed singly to a common termination
or the continuous GND rail with a large cross-section. This common termination may be con-
nected with the system’s PE conductor at one point.
Since only currents 0/4 to 20 mA are used in analog signal exchange between the units and
these are interpreted as a four--pole measurement (differential amplifier with electronic po-
tential isolation), voltage dips on ground are not interpreted as errors (see figures 2-27, page
124 to 2-33, page 126).
The signal--to--noise ratio on digital signals is so great that voltage dips on the GND rail can
be ignored.