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WIKA DPT-10 User Manual

Page 87

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The status byte corresponds to profile 3.0 "Profibus PA Profile for Process Control Devices" coded.
The status "Measured value OK" is coded as 80 (hex) (Bit7 = 1, Bit6 … 0 = 0).

The measured value is transferred as a 32 bit floating point number in the IEEE-754 format.

Byte n

Byte n+1

Bit

7

VZ

Exponent

Bit

6
2

Bit

5
2

Bit

4
2

Bit

3
2

Bit

2
2

Bit

1
2

Bit

0
2

Bit

7
2

Bit

6
2

Bit

5
2

Bit

4
2

Bit

3
2

Bit

2
2

Bit

1
2

Bit

0
2

Sign

Bit

Significant

7

6

5

4

3

2

1

0

-1

-2

-3

-4

-5

-6

-7

Byte n+2

Byte n+3

Bit

7
2

Significant

Bit

6
2

Bit

5
2

Bit

4
2

Bit

3
2

Bit

2
2

Bit

1
2

Bit

0
2

Bit

7
2

Bit

6
2

Bit

5
2

Bit

4
2

Bit

3
2

Bit

2
2

Bit

1
2

Bit

0
2

Significant

-9

-10 -11 -12 -13 -14 -15 -16 -17

-18 -19

-20 -21 -22 -23

-8

Value = (-1)

VZ

2

(Exponent - 127)

(1 + Significant)

Fig. 58: Data format of the measured value

Coding of the status byte associated with the PA output value

Status
code

Description according to Pro-
fibus standard

Possible cause

0x00

bad - non-specific

Flash-Update active

0x04

bad - configuration error

l Adjustment error
l Configuration error with PV-Scale (PV-Span too small)
l Unit irregularity
l Error in the linearization table

0x0C

bad - sensor failure

l Hardware error
l Converter error
l Leakage pulse error
l Trigger error

0x10

bad - sensor failure

l Measured value generation error
l Temperature measurement error

0 x 1f

bad - out of service constant

"O

ut of Service" mode switched on

0 x 44

uncertain - last unstable value

Failsafe replacement value (Failsafe-Mode = "Last value" and
already valid measured value since switching on)

0 x 48

uncertain substitute set

l Switch on simulation
l Failsafe replacement value (Failsafe-Mode = "Fsafe value")

0 x 4c

uncertain - initial value

Failsafe replacement value (Failsafe-Mode = "Last valid value" and
no valid measured value since switching on)

0 x 51

uncertain - sensor; conversion
not accurate - low limited

Sensor value < lower limit

0 x 52

uncertain - sensor; conversion
not accurate - high limited

Sensor value > upper limit

0 x 80

good (non-cascade) - OK

OK

0 x 84

good (non-cascade) - active
block alarm

Static revision (FB, TB) changed (10 sec. active, after the parameter
of the static category was written)

Differential pressure transmitter DPT10 - metal measuring diaphragm • Profibus PA

87

11 Supplement

37245

-

EN

-100120