User Manual

RF-Orchestra!™ Transmitter Installation and Operation Maintenance
July 2000 6880493G02-C 6-9
Check for Timing Chain Errors on the RF-O! Transmitter
Check the alarm and error log (RFO FIPS: a 99 and a 104) for details of any errors listed
below that indicate 1-PPS synchronization problems:
• S_PAGING_DISABLED
Check for paging disabled (RFO FIPS: r 100). This value should be 0. Use RFO FIPS: a83
to determine active disable source(s).
• E_SYNTH1_LOCK_FAILURE, E_SYNTH2_LOCK_FAILURE, or
E_EXCITER_FRU_FAIL_ALARM
If any of these errors are in the error log, and the condition still exists, the Exciter Locked
LED on the front of the RF-O! transmitter should be off. The exciter should fail exciter
diagnostics (RFO FIPS: a 188 c). Erase the error log (RFO FIPS: a 111), turn the RF-O!
transmitter Power switch off, and make sure that the OCM and the exciter are properly
inserted in the chassis. Turn the Power switch on and check for these errors again (RFO
FIPS:
a 104). If any of these errors are in the log, replace the exciter.
• E_PENDULUM_NOT_LOCKED or E_PENDULUM_REFERENCE_FAILURE
The 16.8 MHz clock is created by phase locking the crystal oscillator to the 10 MHz
UHSO reference. This task is accomplished by programming the synthesizer to divide the
16.8 MHz clock by 168 and the 10 Mhz reference by 100. The two 100 kHz clocks created
by the division are phase compared. The phase difference is used to drive the VCO.
Outputs from the synthesizer can be used to diagnose this circuit. Run the OCM limited
diagnostics command (RFO FIPS: a62). If diagnostics results indicate that the VCO is not
locked, replace the OCM.
• <E_HIGH_STABILITY_REFERENCE_FAILURE>
This error indicates that the 10 MHz reference may be absent. Check the coaxial cable
connection from J11 on the RF-B! transmitter controller backplane to J11 on the RF-O!
transmitter backplane. The daisy chained cable should have a 50 ohm termination at the
end. Also, the synthesizer may be incorrectly programmed. The SPI bus coming from the
host processor (MC68360) is a serial bus that is daisy chained to other devices like the
synthesizers in the exciter, Tranlin, crystal oscillator, and PA sensors. Run the OCM
Diagnostics command to check internal hardware (RFO FIPS: a62). If diagnostics results
indicate that the 10 MHz reference is not locked, replace the OCM.
• E_1PPS_INITIAL_SEARCH_FAILURE
Check the connection between J4 on the RF-B! transmitter controller backplane and J4 on
the RF-O! transmitter backplane.