Ross 4500DR-104-07, User Manual, Page: 142 / 161

142 • GPS Option SRG-4500 User Guide (v7.0)
Validating the License
Refer to “ Option Enable Menu ” on page 88 for details on installing and verifying the licensed options on the
SRG-4500. Keep in mind that:
• A valid license key will have between each 4 character group, a "-". For example, option code
2930c49c5a99
will show as
2930-c49c-5a99
.
• If the option key is invalid, you will see the entered value with "." between the groups and "
- Invalid
" after the
entry.
Locking to GPS
To verify that the SRG-4500 is locking to a GPS source:
1. Follow the steps in “
Locking the SRG-4500 to GPS ” on page 139.
2. Does the SRG-4500 report any satellites in view?
• This information is reported in the Slot 12 System Time > GPS Time tab. Also refer to “ GPS Status ” on
page 74.
3. Has enough time been allowed for the SRG-4500 to acquire and lock to GPS? Keep the following in mind:
• The Global Navigation Satellite System (GNSS) only transmits a complete UTC-GNSS time message once
every 12.5 minutes. When powering up the GNSS receiver it is best to wait 12.5 minutes before relying on
the GNSS time.
• The navigation message is transmitted by the satellite on the L1 data link at a rate of 50 bits per second. The
message structure uses a basic format of a 1500 bit long frame (30 seconds) made up of five sub-frames with
each sub-frame being 30 bits long. Sub-frames 4 and 5 are repeated 25 times each, so that a complete
message will require the transmission of 25 full frames (12.5 minutes).
• The UTC offset is only transmitted once per frame, so it is only transmitted once every 12.5 minutes.
Depending where you were in the cycle when the GNSS receiver is first switched on, it can thus be up to
12.5 minutes until the UTC offset value is transmitted from a satellite.
4. Does clicking the
GPS Reboot
button (on the Slot 0 > Genlock tab DashBoard) resolve the issue?
Cabling
To troubleshoot the physical connections in your GPS setup:
1. Is the SMB snap-fit connector properly seated on the end of the GPS cable?
2. Is the antenna cable installed without kinks/abrasions/violating bend radius? Keep the following in mind:
a. Are all cables properly dressed and have appropriate strain relief?
b. Check at connectors that they have not been abused or have excessive bend radius. Remember that
acceptable LMR195 radius is at 2.0” (50.8mm) and LMR400 radius is at 4.0” (101.6mm).
GbE / PTP
100-BaseT
GPS 1Hz 10MHz IN 10MHz WK/TTL1 WK/TTL2 6Hz/TTL3 DARS AES 1 AES 2 BALANCED AUDIO/AES/LTC
COMPOSITE BLACK 1 REF LOOP TRI/BLACK 2 TRI/BLACK 3 TRI/BLACK 4 SDI 2 BLACK SDI 1 SDI 1 BLACK SDI 2
SDI 4 BLACK SDI 3 SDI 3 BLACK SDI 4
TNC Plug
SRG-4500
TNC Jack
SMB Jack
FME Plug
FME Jack
GPS Antenna
2
1
3
3
4