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Operations Manual, HPA2, Compact Outdoor SSPA
11.1.6 Serial Communication Examples
The following shows an example of a communication exchange between a PC and Compact
Outdoor Amplifier, assuming the following:
•
SSPA Network Address = 5
•
Host Computer Network Address = 10
•
Request ID = 0x6F
The Host PC Request String is: (refer to
Table 11-5
)
Byte Position Byte Value (Hex) Description
1
AA
Frame Sync Byte 1
2
55
Frame Sync Byte 2
3
5
Destination Address of Compact Outdoor SSPA
4
A
Source Address of PC sending Request String
5
0
Protocol Version Compatibility Field must always be 0
6
6F
Request ID byte is set by originator, will be echoed back by respondent
7
1
Command field for “Get” type request
8
0
“SSPA Settings” tag indicates which data from respondent is required in
response frame
9
1
Data Address field indicates the beginning data address inside of the
“SSPA Settings” data set to 1 (first element)
10
A
Data Length field indicates how many data bytes of the “SSPA Settings”
requested from the amplifier
11 8A
Arithmetic
checksum
of bytes number 3 through 10
