Siemens S5-135U/155U - Manual (Page 491)

9-109
System Manual
C79000-G8576-C199-06
9.7.8 Connecting Loads to the 470 Analog Output Module
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
ANA
must not exceed 3 V.
+
–
Load (Voltage)
+
–
Load (Current)
QV(x)
S+(x)
S – (x)
QI (x) I
MANA
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
ANA
Ground terminal for the analog section
When current and voltage outputs are used on the 470-4UA/-4UC... analog
output modules, connect the loads as follows:
+
–
+
–
QV0
M
ANA
S+0
S–0
QI0
+
–
+
–
+
–
+
–
+
–
M
ANA
M
ANA
Current
Output
Only
Jumper
Jumper
QV1
S+1
S–1
QI1
QV2
S+2
S–2
QI2
QV3
S+3
S–3
QI3
QV4
S+4
S–4
QI4
_
Jumper
Jumper
Not Current
and Not Voltage
Output
Figure 9-40 Connecting Loads
Connecting Loads
to Current and
Voltage Outputs
Analog Input/Output Modules