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AXL F AI4 I 1H

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12.3

Calculation of the measured value from the

process data input value

The following examples explain the calculation of the mea-

sured value from the process data input value for the mea-

suring range 4 mA to 20 mA.

PD IW = Process data input word = input data

IB IL format

Resolution = (20 mA - 4 mA) / 30000 = 0.0005333

Measured value = PD-EW x 0.0005333 mA +4 mA

S7-compatible format

Resolution = (20 mA - 4 mA) / 27648 = 0.0005787

Measured value = PD IW x 0.0005787 mA + 4 mA

Parameter, diagnostics and

information (PDI)

Parameter and diagnostic data as well as other information

is transmitted via the PDI channel of the Axioline F station.

The standard and application objects stored in the module

are described in the following section.

The following applies to all tables below:

Please refer to the UM EN AXL F SYS INST for an explana-

tion of the object codes and data types.

Example 1

PD IW

493F

hex = 18751dec

Value x resolution

18751 x 0.000533 mA = 10 mA

+ 4 mA

10 mA + 4 mA = 14 mA

Measured value

14 mA

Example 1

PD IW

6C00

hex = 27648dec

Value x resolution

27648 x 0.0005787 mA = 16 mA

+ 4 mA

16 mA + 4 mA = 20 mA

Measured value

20 mA

Example 2

PD IW

F940

hex -> FFFFhex - F940hex + 1

= -1728

dec

Value x resolution

-1728 x 0.0005787 mA = -1 mA

+ 4 mA

-1 mA + 4 mA = 3 mA

Measured value

3 mA

Abbreviation

Meaning

Number of elements

Length of the elements in bytes

RRead

WWrite

Every visible string is terminated with a zero

terminator (00

hex). The length of a visible

string element is therefore one byte larger

than the amount of user data.

For detailed information on PDI and the ob-

jects, please refer to the

UM EN AXL F SYS INST user manual.

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