Siemens S5-155U System Manual page 484

The 470 Analog Output Module
9.7.8
Connecting Loads to the
470 Analog Output Module
Connecting loads to current
and voltage outputs
QV 0
QV 1
S + 0 S + 1
+
-
S - 0 S - 1
QI 0
QI 1
+
-
M
ANA
Figure 9-40 Connecting Loads
9 - 114
The voltage at the load is measured at a high resistance via the sensor
lines (S+/S-) of voltage output QV, so that voltage drops on the load
lines do not falsify the load voltages. Lines S+(x) and S-(x) should
therefore be directly connected to the load (four-wire circuit). The
voltage drops on the lines from QV(x) to the load and from the load to
M must not exceed 3 V.
ANA
QV (x)
S+ (x)
S - (x)
QI (x)
M
ANA
Figure 9-39 Connecting Loads
QV(x) Voltage output, voltage on Channels 0 to 7
QI(x) Current output, current on Channels 0 to 7
S+(x) Sensor line (+) for Channels 0 to 7
S- (x) Sensor line (-) for Channels 0 to 7
M Ground terminal for the analog section
ANA
When current and voltage outputs are used on the 470-4UA/-4UC...
analog output modules, connect the loads as follows:
QV 2
S + 2
+ +
- -
S - 2
QI 2
+ +
- -
+
Load (Voltage)
-
I
+
Load (Voltage)
-
QV 3 QV 4
Jumper
S + 4
S + 3
S - 4
S - 3
_
QI 3 QI 4
+
-
Jumper.
M M
ANA ANA
Current Not Current
Output and Not
Only Voltage
Output
C79000-B8576-C109-03
Jumper
Jumper
System Manual