Siemens Sitrans LR400 Instruction Manual page 103

The first 4 bytes are the floating point representation (IEEE) of the variable. The variables
are the outputs of the function block. The default setting for the variable level is meters.
The default setting for the variable volume is m
is kg. You can change the settings of the variables by changing the settings of the
function block. This is typically done using PDM.
The 5th byte is the status word and the list of possible values is given in the chart on
page 100.
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.
If you select a Free Place module to fill one of the slots, this will affect the byte number.
Example 1:
Free
Place
Volume
Mass
Example 2:
byte1
Level
Free
Place
Mass
7ML19985FH06 SITRANS LR400 (7ML5421) – INSTRUCTION MANUAL
Floating Point
— —
byte 1 byte 2 byte 3
byte 6 byte 7 byte 8
Floating Point
byte 2 byte 3
— —
byte 6 byte 7 byte 8
3
. The default setting for the variable mass
— —
byte 4
byte 9
byte 4
— —
byte 9
Status
—
byte 5
byte 10
Status
byte 5
—
byte 10
Page 99