Festo CPX-2AA-U-I, Электронное руководство

Страница: 71 / 228

2. Analogue input module CPX−2AE−U−I
2−27
Festo P.BE−CPX−AX−EN en 0503b
Data format VZ + 15 bits linear scaled"
The 12−bit digital values, which exist after the A−D conversion
of the analogue input signals, are linearly scaled to the data
range defined by the scaling end values (limit values) and
output in the input word (see section 2.4.5, Fig.2/5).
Data format VZ + 12 bits right−justified"
The 12−bit digital values, which exist after the A−D conversion
of the analogue input signals, are output unmodified in the
input word (see also example in section 2.4.1, Fig.2/3).
Data format VZ + 15 bits left−justified" and
data format VZ + 12 bits left−justified + diagnosis"
The 12−bit digital values, which exist after the A−D conversion
of the analogue input signals, plus the preceding sign bit are
arranged left−justified in the data format. The three zeros at
the end cause the output data word to correspond to the
12−bit digital value after A−D conversion multiplied by 8
(providing there is no wire fracture diagnosis).
The following diagram shows an example of the data format
VZ + 15 bits left−justified":
1
Analogue input
values
2
Digital signals after
A−D conversion
3
Available digital
signals scaled to the
end value of the data
range
1
2
3
32760
0 4095
0
0 V
0 mA
4 mA 10 V
20 mA
20 mA
Fig.2/4: Example of data format VZ + 15 bits left−justified"