Siemens simatic c7-621 Hardware Installation Manual page 91

Connecting Loads Connecting loads to a single voltage output is only possible with a 2-wire
to a Voltage
connection.
Output
2-Wire Connection
The connection of loads to a voltage output using a 2-wire connection is
made at the analog output AO-U and the reference point of the measuring
circuit AO-M.
Figure 7-6 shows the connection of loads to a voltage output of a
non-floating analog output module with a 2-wire connection.
Figure 7-6
C7-621 / C7-621 AS-i Control Systems
C79000-G7076-C621-01
C7-621
Logic
C7-CPU
L+
Input 24V DC
M
NC
NC
Connection of Loads to a Voltage Output of a Non-Floating Analog
Output Module
C7-621 Analog I/Os
AO-U
DAC
M
AO-M
Functional ground
R
L
7-9