Wika D-11-7 Manual do Utilizador descarregar pdf (Página 16)

16 WIKA operating instructions pressure transmitter model D-1x-7

2478159.05 12/2011 GB/D/F/E

6. Commissioning, operation

6.3 Message structure

In the send message the transmission of the measured value, error detection and service requests are

combined. The D-1x-7 supports only DP-V0 and therefore a cyclic data exchange.

Below, the encoding of the individual elements is claried:

The representation is not carried out as a two's complement.

Send message

Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 Byte 8

Pressure

value MSB

with sign

Pressure

value

LSB

Factor,

Unit

Error status Error code Service

request

Service

response 1

Service

response 2

Measured value Error detection Services

Measured value

Number format of the measured value: 16 bit integer (sign and magnitude representation)

Pressure value MSB (Byte 1): Bit 7 contains the algebraic sign

Bit 6 ... 0 contains the highbyte of the measured value

Pressure value LSB (Byte 2): contains the lowbyte of the measured value

Factor (Byte 3): contains the measurement type, unit and exponent

Pressure value MSB (byte 1) Pressure value LSB (byte 2)

7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0

Pressure value

(Note the sign bit and factor)

Pressure value sign

0 = positive

1 = negative

1 2 ... 11 12 13 14 15 16 17 18 19 20 21 ... 111 112

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Wika D-11-7 Manual do Utilizador Página 16