Siemens LMV3 series User Manual

Technical Instructions LMV Series
Document No. LV3-1000
Section 7 Page 2 SCC Inc.
Checksum (CRC16)
Transmission errors are detected with the help of the checksum (CRC16). If an error is detected during
evaluation, the respective device will not respond.
Calculation
scheme
CRC = 0xFFFF
CRC = CRC XOR ByteOfMessage
Fo
r (1 to
8)
CRC = SHR (CRC)
if (flag shifted to the
right = 1)
then
CRC = CRC XOR
0xA001
else
while (not all ByteOfMessage
edit
ed)

The low-byte of the checksum is transmitted first.
Example
Data
in
qu
i
ry:
Reading 2 words from address 6 (CRC16 = 0x24A0)
0B
03
00
06
00
02
A0
24
CRC16
Reply: (CRC16 = 0x0561)
0B
03
04
00
00
42
C8
61
05
Word 1
Word 2
CRC16
Mapping long values
Byte High
Byte Low
Byte High
Byte Low
Word Low
Word High
Erroneous access to parameters of the LMV3
Reading
When attempting to read non
-
existing paramaters
, a substitute value will be sent.
The substitute value is fixed at 0xFFFF.
Writing
When attempting to write to
non
-
existing parameters, or to parameters disabled for
building automation mode, the value of the parameter will not be changed and no
response will be sent.

Siemens LMV3 series Specifications

General

Brand	Siemens
Model	LMV3 series
Category	Control Unit
Language	English