Mentor XL
12.9.2
GPS Status Menu (read only)
GPS
Status
Satellites
number used
Serial Data
OK
Not OK
1 PPS
OK
Not OK
Lock
Locked to 1 PPS
Not locked to 1 PPS
Receiver
Locked to Satellites
Not locked to Satellites
•
Satellites
. The time taken to acquire satellites can be 10 or 15 minutes, since the almanac
data is broadcast fairly infrequently. The menu displays the number of satellites actively
used. On first power up after installation, this process can take much longer.
•
Serial Data OK / Not OK:
indicates whether the serial data from the receiver is present or
not.
•
1 PPS OK / Not OK:
reports the presence of 1 PPS as a general diagnostic aid.
•
Lock
indicates whether the board is locked to the GPS 1 PPS signal.
•
Receiver
indicates the current status of the GPS receiver.
12.10
A
BSOLUTE
T
IME
R
EFERENCE
(ATR)
The concept of ATR is covered by SMPTE Proposal 404 and is also known as “SMPTE epoch”. It
defines a starting point of midnight on January 1
st
1958, at which time all generating equipment is
deemed to be phase locked.
In order to make use of the ATR definition, precise date/time provided by the GPS receiver is
required. This allows the current state of the Mentor XL to be computed with regard to the epoch as
defined by ATR. By accurate determination of current time, any ATR equipped items may be locked
together again.
Page 70 of 84
Trilogy Communications
