Shaw AcuDew, Инструкция по эксплуатации

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16 Appendix E – Communications Protocol
RS485 Request Protocol (as seen by AcuTrak)
Byte Description
0, first
Preamble
255
1 255
2 255
3 255
4 255
5 Master-to-Slave 2
6 Address 0 to 32
7 Command 24
8 Data Length 1
9 Data Bytes 0
10, last Checksum 8-bit Arithmetic Exclusive-Or of bytes 5 to 9
RS485 Reply Protocol (as seen by AcuTrak)
Byte Description
0, first
Preamble
255
1 255
2 255
3 255
4 255
5 Slave-to-Master 6
6 Return Address
(128 for Address 0) 8-bit Arithmetic OR of
Address with 128
7 Command 24
8 Data Length 6
9
Status
Bits 15 - 8
10 Bits 7 - 0
11
Data
Process Value
12 Single Precision (4-Byte Float)
12 IEEE 754 Format
14 Big-endian (first byte = msb)
15, last Checksum 8-bit Arithmetic XOr of bytes 5 onwards
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