Paradise Datacom 4 RU Chassis, Руководство по эксплуатации

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4 RU SSPA Chassis Operations Manual 201627 REV X 87
7.3 Access SSPA subsystem through Packet Wrapper technique
Features introduced in firmware version 4.03 allow send requests directly to a remote
SSPA subsystem. In this mode, the RCP redirects requests from its Serial Main or
Ethernet port to its Local serial port, connected to the SSPA (see
Figure 7-8
). Packet
wrapper requests are associated with longer response times, which have to be
accounted in the host M&C software. This mode can be useful for advanced remote
diagnostic of the attached SSPA subsystem.
All Packet Wrapper request frames must be “Data Set” command requests. Each
frame intended for redirection must be included in request packet Data Fields. Packet
Wrapping frame M&C should follow the same rules as for any other request frames
with one exclusion — the Data Address field will represent the number of bytes
expected back from the remote SSPA. These bytes will be redirected back to the Host
M&C in the Data Field response packet. The response packet will not be sent until the
specified number of bytes is collected in the RCP2 buffer.
Maximum length of the data fields in both directions should not exceed 32 bytes. In the
diagram represented in
Figure 7-8
, Request frame A is the Packet Wrapper frame. It
contains Request frame B, intended to be redirected to the remote SSPA.
Protocol ID
0
Request ID
0 to 255
Command
0 - 1
Data Tag
6
Response Length
n = 11 + m
Data Length
11 to 11 + m
Header
4 Bytes Command Preamble
6 Bytes
Request Frame B
11 to 11 + n Bytes
Trailer Checksum
1 Byte
Request Frame A
Protocol ID
0
Request ID
0 to 255
Command
0 - 1
Data Tag
0 - 4
Data Address
0 to 255
Data Length
m = 1 to 128
Header
4 Bytes Command Preamble
6 Bytes
Data Field
0 to m Bytes
Trailer Checksum
1 Byte
Request Frame B
Protocol ID
0
Request ID
0 to 255
Command
2 - 3
Data Tag
6
Error Status
0 to 5
Data Length
11 + m
Protocol ID
0
Request ID
0 to 255
Command
2 -3
Data Tag
0 - 4
Error Status
0 to 5
Data Length
m = 1 to 128
Header
4 Bytes Command Preamble
6 Bytes
ResponseFrame B
11 + n Bytes
Trailer Checksum
1 Byte
Response Frame A
Header
4 Bytes Command Preamble
6 Bytes
Data Field
m Bytes
Trailer Checksum
1 Byte
Response Frame B
Figure 7-8: Packet Wrapper technique
SSPA Chassis
RCP
Propogation Delay 1-10 mS
Propogation Delay 1-50 mS Propogation Delay 1-50 mS
Host PC
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R
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R
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J5 Local
J4 Main or
J9 Ethernet