AIFB1 and AIFB2 return 5 bytes of data each:

 

 

Floating Point

 

AIFB1

 

 

 

 

 

byte 1

 

byte 2

 

byte 3

 

 

 

 

 

 

 

 

 

 

 

 

AIFB2

byte 6

 

byte 7

 

byte 8

byte 4

byte 9

Status

byte 5

byte10

H: Communication PA

The first 4 bytes are the floating point representation (IEEE) of the variable. The variables are the outputs of the function block. The 5th byte is the status word and the list of possible values is given in the chart below.

The 5 bytes must be read consistently, in a contiguous chunk: they cannot be read byte by byte, and cannot suffer an interrupt. If you are using an S7-300 / 400, you will need to use SFC14 DPRD_DAT: Read Consistent Data of a Standard PD Slave.

Status Byte

 

Status Codes for Good Quality

 

Values in hex notation

 

Description

 

 

 

 

 

 

0x80

 

Data is GOOD.

 

 

 

 

 

 

0x84

 

A parameter in the function block has been changed: status

 

 

active for 10 s

 

 

 

 

 

 

 

 

 

0x89

 

Active low warning.

 

 

 

 

 

 

0x8A

 

Active high warning.

 

 

 

 

 

 

0x8D

 

Active low alarm.

 

 

 

 

 

 

0x8E

 

Active high alarm.

 

 

 

 

 

 

 

Status

Codes for Bad Quality

 

Values in hex notation

 

 

Description

 

 

 

 

 

 

0x10

 

 

This could be caused by LOE or by a sensor malfunc-

 

 

 

tion: value is BAD.

 

 

 

 

 

0x01

 

 

There is an error in the configuration of the function

 

 

 

blocks in PROFIBUS PAa.

 

 

 

 

 

 

 

 

The function block has been placed out of service.

 

0X1F

 

 

(You will see this only if you read status word via

 

 

 

acyclic services, after placing the function block out of

 

 

 

 

 

 

 

 

service.)

 

0xC4

 

 

Bad configuration: value is BAD.

 

0XDE

 

 

AI block out of service: value is BAD.

 

a.This could happen when a firmware download has been done, but a system reset has not been done. This could also happen if the function blocks are not configured properly using PDM or acyclic services.

Page H-96

SITRANS LR 460 (PROFIBUS PA) – INSTRUCTION MANUAL 7ML19985JM01

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Siemens LR 460 instruction manual Status Byte, Status Codes for Good Quality, Codes for Bad Quality, H-96