DOC 6501_Release V
ATS-6501 Users Guide
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3.4.3.6 Raw TIC Data Port (2101) ...................................................................... 69
3.4.4 File Transfer Protocol (FTP) ....................................................................... 70
3.4.5 Network Time Protocol (NTP) ................................................................... 70
3.4.5.1 NTP Authentication ................................................................................. 70
3.4.5.2 NTP Server .............................................................................................. 71
3.4.5.3 NTP Clients ............................................................................................. 73
3.4.6 Simple Network Management Protocol (SNMP) ....................................... 73
3.4.6.1 Management Information Base (MIB) .................................................... 73
3.4.6.2 SNMP2 .................................................................................................... 73
3.4.6.3 SNMP3 .................................................................................................... 73
3.4.6.4 Testing SNMP3 ....................................................................................... 74
3.4.6.5 SNMP Traps ............................................................................................ 75
3.4.7 Secure Shell (SSH) Authentication ............................................................. 75
3.4.7.1 Creating a SSH New Key ........................................................................ 75
3.4.7.2 Transferring a SSH Key .......................................................................... 75
3.5 Local User Accounts .......................................................................................... 75
3.6 Status Command ................................................................................................ 76
3.7 GPS Data Logging (Not available on SAASM Type I) ..................................... 77
3.7.1 FTP Data Logging ....................................................................................... 77
3.7.2 Real Time Data Logging ............................................................................. 80
3.8 WAAS Satellites (Not available in SAASM version) ........................................ 81
3.9. System Verification ............................................................................................ 82
4 Theory of Operations ...................................................................................................... 96
4.1 Generation of Timing Signals ............................................................................ 96
4.2 GPS ..................................................................................................................... 96
4.3 Deterministic PLL (6501B only) ........................................................................ 96
4.4 Output Signals .................................................................................................... 97
4.5 GPS Data Collection (Not available in SAASM Type 1) .................................. 97
4.6 Startup Sequence ................................................................................................ 98
5 Maintenance ................................................................................................................. 100
5.1 Internal Inspection ................................................................................................ 100
5.2 Antenna and Antenna Cable Inspection ................................................................ 100
5.3 Fan Filter ............................................................................................................... 101
6. Troubleshooting ............................................................................................................ 102
6.1 Front Panel Indications ..................................................................................... 102
6.2 Alarm Light ...................................................................................................... 102
6.2.1 Power Supplies .......................................................................................... 103
6.2.2 Outputs Enabled ........................................................................................ 104
6.2.3 GPS Performance ...................................................................................... 105
6.2.3.1 Poor GPS Receiver Performance .......................................................... 106
6.2.3.2 GPS Not Tracking ................................................................................. 107
6.2.4 Internal Clocks .......................................................................................... 108
6.2.5 External Reference .................................................................................... 109
6.2.6 NTP Server ................................................................................................ 112
6.2.7. PTD Value is Noisy .................................................................................. 112
6.2.8 Over Temperature and Fans ...................................................................... 112