Messages
Chapter 5
WAAS GUS Signal Generator User Guide Rev 1
37
5.1.4
Status Message
The Status Message contains the status message fields. The L1/L5 Signal Generator sends the Status Message to the
WMP after every 1PPS update pulse. The status message contains the uplink range, the current setting of option
switches, any errors that may have occurred in the last 1 second epoch and hardware status. The status message is
transmitted from byte [0] through [33]. The WMP may need to swap bytes accordingly in order to recover the
original data field (prior to transmission by the Signal Generator). The following sections indicate the data fields for
a status message.
Table 32: Status Message Fields
Table 33: Uplink Range Fields
5.1.4.1
Uplink Range Code Chip Sub-Phase Field
This field contains the sub-phase of the code chip latched, within the current 1 ms epoch, upon detection of a 1PPS
update pulse.
shows the Uplink Range Code Chip Sub-Phase field byte and bit order.
Field
Bytes
Byte Position
Description
3-1
2
Byte [5:6]
Uplink Range Code Chip Sub-Phase
3-2
2
Byte [7:8]
Uplink Range Code Chip Counter
3-3
2
Byte [9:10]
Uplink Range Symbol Counter
3-4
1
Byte [11:11]
Switch Status
3-5
2
Byte [12:13]
Error Status
3-6
1
Byte [14:14]
Hardware Status
3-7
1
Byte [15:15]
For future use. Set to zero.
3-8
4
Byte [16:19]
Reset Command Second Epoch Counter
Range = 0 – (2
31
-1)
3-9
4
Byte [20:23]
Hardware Reset Second Epoch Counter
Range = 0 – (2
31
-1)
3-10
2
Byte [24:25]
Firmware Version Number
3-11
2
Byte [26:27]
FPGA Version Number
3-12
1
Byte [28:28]
Signal Generator State
3-13
5
Byte [29:33]
For future use. Set to zero.
Data Byte Position
Description
Byte [5:6]
Uplink Range Code Chip Sub-Phase
Resolution = 1 x 2
-16
code chip
Byte [7:8]
Uplink Range Code Counter
Byte [9:10]
Uplink Range Symbol Counter
