Analog Value Processing
Figure 11-10 shows how to connect loads to the current outputs of the following modules.
•
470-8MB12 (2x±20 mA)
•
470-8MC12 (2x+4 to 20 mA).
1
3
2
L+
M
24 V DC
(4/8)
QI
R
Figure 11-10. Load Connection via a Two-Wire Circuit (6ES5 470-8MB12 or 6ES5 470-8MC12)
11.5.2 Analog Value Representation of Analog Output Modules
Table 11-14 shows how the analog output value has to be stored in the process image output table
(PIQ).
Table 11-14. Representation of an Analog Output Value as a Bit Pattern
Bit number
Analog value represent.
Key:
S
sign bit
X
irrelevant bits
11-20
5
7
9
10
4
6
8
(6/10)
Terminal assignment
M
Terminals
ANA
L
High Byte
7
6
5
4
3
10
9
8
7
S
2
2
2
2
Key:
QI:
Analog output "Current"
M
:
Chassis ground terminal
ANA
of the analog unit
2
1
0
7
6
5
6
5
4
3
2
1
2
2
2
2
2
2
S5-100U
Low Byte
4
3
2
1
0
0
2
X
X
X
X
EWA 4NEB 812 6120-02b