Merge branch 'prefer_ltc' into 'branch-5.1'

Switch order so that IOP prefers Ligo Timing Card to old TDS system

See merge request !622

src/fe/controllerIop.c

@@ -368,12 +368,12 @@ fe_start_controller( void )
     pLocalEpics->epicsOutput.timeDiag = 0;
 
     /// \> Determine code startup synchronization and timing source.
-    // if Contec 1616 BIO present, Gen1 TDS receiver will be used for timing.
-    if ( cdsPciModules.card_count[ CON_1616DIO ] )
-        syncSource = SYNC_SRC_TDS;
     // If PCIe timing card found (IOC Gen2), use that for startup sync
-    else if ( cdsPciModules.card_count[ LPTC ] > 0 )
+    if ( cdsPciModules.card_count[ LPTC ] > 0 )
         syncSource = SYNC_SRC_LTC;
+    // if Contec 1616 BIO present, Gen1 TDS receiver will be used for timing.
+    else if ( cdsPciModules.card_count[ CON_1616DIO ] )
+        syncSource = SYNC_SRC_TDS;
     // If not on aligo timing system, will try to sync to 1PPS signal on ADC
     // This is legacy support for non-LIGO sites that still use an eLIGO
     // timing system.