Siemens LMV 5 Series, Technical Instructions, Page: 272 / 374

Technical Instructions LMV Series
Document No. LV5-1000
Section 8 Page 2 SCC Inc.
Example Data query: 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 Words
B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14 B15
Byte High Byte Low
Transmission mode: The LSB (least significant bit) is transmitted first.
Mapping Long Values
Byte High Byte Low Byte High Byte Low
Word Low Word High
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
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
Reply of slave
Transmission time = n characters * 1000 * x bits / Baud rate
Marking for end of reply
3.5 characters * 1000 * x bits / Baud rate
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