Operations Manual, HPA3, Mini Compact Outdoor SSPA
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varies by the amount of attached data bytes. It may contain 11+N bytes where N is the
amount of requested data bytes from a particular table, specified in Data Length field.
The Set Request command allows the sender to actively change parameters for the re-
ceiver’s internal configuration. The Set Request frame must contain a number of bytes in the
Data Field as specified in Data length field. The frame size must be 11+N bytes, where N is
the length of the attached data structure. The receiver will respond with a frame where the
command field will be set to a Set Response designator. The frame length is equal to the
Request frame. The byte value for each command is given in
Table 8-2
.
8.1.2.4 Data Tag
The SSPA internal structure is organized in several tables, all of which share similar function-
ality and internal resources. To access the various tables, the data tag must be specified in
the request frame. The data associated with certain tags is read only. Therefore only the
“Get” command request would be allowed to access these data tags. The SSPA will return an
error on attempts to issue a “Set” request to a read-only table tag. Various tables may contain
values formatted either in 1 or 2 bytes format. See
Table 8-3
.
Command Name
Command Byte Value
Set Request
0
Get Request
1
Set Response
2
Get Response
3
Table 8-2: Command Byte Values
Tag Name
Byte
Value
Minimum
valid length
of Data Field
Description
System
Tag Settings
0
1 byte
This tag allows accessing various system settings on remote unit.
Host access status: Full Read/Write access. Settings can be modi-
fied at any time. Some settings may require hardware reset of the
remote SSPA unit.
System
Threshold Tag
1
2 bytes
This tag allows access to the critical unit thresholds. Host access
status: Read Only.
System
Conditions Tag
3
1 byte
This tag allows access to the unit’s internal conditions flags, such
as fault status or current system status. Host access status: Read
only. This type of data cannot be set or modified remotely.
ADC Channels
Access Tag
4
2 bytes
This tag allows access to the unit’s internal Analog to Digital con-
verter. Host access status: Read only. This type of data cannot be
set or modified remotely.
Packet
Wrapper
6
1 byte
Tag is not used in CO SSPA protocol.
Table 8-3: Data Tag Byte Values
Reserved
2
N/A
This tag is reserved and not used for CO SSPA applications.
Reserved
5
N/A
This tag is reserved for factory usage only.
