Siemens SIMATIC S5-90U System Manual page 460

Module Spectrum
Connection of the Module
Figure 15-19 shows how to connect loads to the voltage outputs of the modules.
The sensor lines (S+ and S-) must be directly connected to the load, so that the voltage is
measured and regulated directly at the load. In this manner, voltage drops of up to 3 V per line can
be compensated for.
The sensor lines can be left out if the resistances of the QV and M lines are negligible compared to
the load resistance. In such a case, connect terminal S + to terminal QV, and terminal S to M
1
L+
M
24 V DC
(4/8) (3/7)
QV S+
R
L
Figure 15-19. Load Connection via a Four-Wire Circuit
Analog Value Representation
Table 15-34. Analog Output Module 470-8MA12 (Bipolar Fixed-Point Number)
Units Output Values
in V
1280 12.5
1025 10.0098
1024 10.0
512 5.0
1 0.0098
0 0
- 1 - 0.0098
- 512 - 5.0
- 1024 - 10.0
- 1025 - 10.0098
- 1280 - 12.5
15-94
S+ S- S+
3 5 7
QV
M QV
ANA
2 4 6 8
(5/9) (6/10) Terminal assignment
S- M Terminals
ANA
(6ES5 470-8MA12)
High Byte
0 1 0 1 0 0
0 1 0 0 0 0
0 1 0 0 0 0 0 0 0 0 0 0 x x x x
0 0 1 0 0 0 0 0 0 0 0 0 x x x x
0 0 0 0 0 0 0 0 0 0 0 0 x x x x
0 0 0 0 0 0 0 0 0 0 0 0 x x x x
1 1 1 1 1 1 1 1 1 1 1 1 x x x x
1 1 1 0 0 0 0 0 0 0 0 0 x x x x
1 1 0 0 0 0 0 0 0 0 0 0 x x x x
1 0 1 1 1 1 1 1 1 1 1 1 x x x x
1 0 1 1 0 0 0 0 0 0 0 0 x x x x
S-
9
Key:
M
ANA
QV:
S±:
M :
10
ANA
R :
L
Low Byte
0 0 0 0 0 0 x x x x
0 0 0 0 0 0 x x x x
S5-90U/S5-95U
.
ANA
Analog output "Voltage"
Sensor line
Chassis ground terminal
of the analog unit
Load resistor
Range
Overrange
Nominal range
Overrange
EWA 4NEB 812 6115-02b