Advantech Wireless SSPBMg-C400-BRE, Инструкция по установке и эксплуатации, Страница: 39 / 46

SSPBMg-C400-BRE
11. APPENDIX A: RS-485 SERIAL COMMUNICATION PROTOCOL
1.1 INTRODUCTION
his Section describes the RS485 serial interface for interconnection between External Network
anagement System (NMS) and Advantech Wireless units.
his protocol supports 2 and 4 wires RS485 interface 9600.N.8.1.
1.2 FRAME STRUCTURE
Eac
7 bytes .
Firs
Mas
ndent Advantech
Wireless unit (0x01 to 0x0F).
unit sends the respond frame to NMS, it left shifts its
unit address by 4. For example, unit with address 0x05 will put 0x50 in the address byte.
aster to Slave: Command byte. The command codes are described in TABLE 10
1
T
M
T
1
h frame starts from start byte 0x55. After this start byte, each frame consists of
t byte:
ter (NMS) to Slave (Advantech Wireless unit): Address of correspo
Slave to Master: When Advantech Wireless
Second byte:
M
.
lave to Master: First data or status byte
hird, forth, fifth and sixth bytes:
aster to Slave: Value of parameter or expansion of command (third byte if applicable)
lave to Master: Remaining data or status bytes
eventh byte:
heck sum, calculated as algebraic sum of bytes 1 to 6.
ll not used bytes always - 0xAA.
ormat for gain, attenuation, level and temperature is a 2-bytes hexadecimal value in 0.1 dB,
.1dBm, 0.1 degree (signed integer).
S
T
M
S
S
C
A
F
0
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