Siemens LMV5 Series Technical Instructions page 272

Technical Instructions
Document No. LV5-1000
Example Data query: Reading 2 words from address 6 (CRC16 = 0x24A0)
0B
Reply: (CRC16 = 0x0561)
0B
Mapping Words
B0 B1 B2 B3 B4
Byte High
Transmission mode: The LSB (least significant bit) is transmitted first.
Mapping Long Values
Byte High
Word Low
Communication Process
Start and end of a data block are characterized by transmission pauses. The maximum permissible time
between two successive characters is 3.5 times the time required for the transmission of one character.
The character transmission time is dependent on the Baud rate and the data format used.
Having a data format of 8 data bits, no parity bit and one stop, the character transmission time is
calculated as follows:
Character transmission time [ms] = 1000 * 9 bits / Baud rate
And with other data formats:
Character transmission time [ms] = 1000 * 10 bits / Baud rate
Process
Section 8
03 00 06
03 04 00
Word 1
B5 B6 B7
Byte Low Byte High
Word High
Data query from the master
Transmission time = n characters * 1000 * x bits / Baud rate
Marking for end of data query
3.5 characters * 1000 * x bits / Baud rate
Data query handling by the slave
Transmission time = n characters * 1000 * x bits / Baud rate
Marking for end of reply
3.5 characters * 1000 * x bits / Baud rate
Page 2
HOME
00 02
00 42 C8
Word 2
B8 B9 B10 B11 B12
Byte Low
Byte Low
Reply of slave
LMV Series
A0 24
CRC16
61 05
CRC16
B13 B14 B15
SCC Inc.