RCI Frame Sync Troubleshoot
Troubleshoot of system:
FXO Inc. is in the process of troubleshooting and testing the RCI Frame Synchronizers built in the 1990ís by Rarick Consulting Inc.† for Lockheed Martin.† These frame synchronizers are used in the TIROS weather satellite ground test system to receive the downlink telemetry and find the proper telemetry stream.
The Test Setup photo shows two RCI Frame Syncs a NAGE Test Monitor box an oscilloscope and a laptop computer.† The laptop computer interfaces to the Frame Sync on the left via an RS-232 connection.† This Frame Sync then communicates with the frame sync on the right via an RS-422 connection.† With this setup, the laptop can command either frame sync.† The frame sync on the right is the known working unit.† Each frame sync has a Simulate output which is used to drive the frame sync under test.† The laptop running a C-program under windows will change the format on the simulate frame sync.† The operator will change the mode of the UUT frame sync and confirm that the UUT goes into lock when both patterns match and go out of lock for different patterns.
SIMULATOR FRAME SYNC with NAGE Monitor and Oscilloscope
Here is a close up of the Simulate Frame Sync.† This unit drives the Clock, Clock 90 and Data into the UUT.† The NAGE Monitor STE on top is connected to the NAGE Output on the UUT.† This box captures the NAGE signals from the UUT and allows for probing of the signals with an oscilloscope.†† Note the gray ribbon cable connects to the UUT Frame Sync.†
FRAME SYNC UNDER TEST (UUT)
FRAME SYNC FRONT PANEL
The program running on the laptop performs all of the commands that could be entered on the keypad of the frame sync unit.†† However, it improves the speed of testing because it is much easier to change Frame Sync configuration using the front panel.† Every possible setup is available from the software front panel.† This compares favorably to using the hardware front panel on the units.† An operator must wade thru multiple menus to do a similar operation.† The software front panel cuts down test time by two out of eight hours.
FRAME SYNC REAR PANEL
The rear panel shows that the Clock and Data signals from the Simulator Frame Sync connect over to the Clock and Data inputs on BNC 1 to the UUT Frame Sync.† During test, the operator is asked to change the configuration such that the UUT Frame Sync simulator outputs are used to drive the known working Frame Sync.† This will test out the UUTs ability of the Simulator outputs.† In addition, the BNC2 inputs will also be tested on the UUT Frame Sync.
TIROS ATNAGE INTERFACE MONITOR
The TIROS ATNAME Interface Monitor box receives the outputs of the UUT Frame Sync and brings those signals to test points.† The NAGE output on the Frame Sync utilizes a differential driver to output to the NAGE.† These drivers are 75109A devices.† These canít easily be monitored directly, so this Interface Monitor box was designed and built to convert the 75109A output signals into TTL levels for display on an oscilloscope.† In addition, A reset switch was added in the Monitor box to perform the Re-sync to the Frame Sync.† This is a signal that the NAGE sends to the Frame Sync to reset.