Siemens S5-135U/155U Manual De Usuario

9-91

System Manual
C79000-G8576-C199-06

After conversion, the digital result is stored in the module’s RAM.
The bits in both bytes have the following significance:

Byte 0

7

6

5

4

3

2

1

0

7

6

5

4

3

2

1

0

2

12

2

2

2

2

2

2

2

2

2

2

2

2

11

10

9

5

7

3

1

8

4

6

2

0

A

E

OV

Byte 1

Binary Value

is not assigned

is set in case of internal error;
in this case, the measured value
is not valid

(is set if the range limit is reached)

Figure 9-32

Digital Result Representation

Bits 0 to 2 in byte 1 have no influence on the measured value, they only give
information on measured-value representation. The following table describes
their significance in more detail.

OV

Overflow bit

 1

 Range exceeded *

E

 Error bit

 1

 Broken wire

A

 Active bit

 0

 Not used

*

A measuring-point overflow does not affect the overflow bits of the other channels;

i.e. the measured values of unaffected channels are correct and can be evaluated.

Please note the following special features:

Bit 7 in the high byte (2

12

) indicates the sign for bipolar measured-value

representation (two’s complement and value with sign).

Bit 6 in the high byte (2

11

) is not used in the case of bipolar

measured-value representation (no overrange).

The 466 module has no overrange.

Selective sampling is not possible with the 466 module 
(active bit is not set).

Analog Input/Output Modules