ACR HAS TCASII TA THEN RA. RESPONDS.

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HANDED OFF TO DFW APCH CTL AT 9000 FT. GIVEN 060 DEG HDG DSCNT TO 5000 FT. TCASII WARNINGS PROGRESSED RAPIDLY; STARTING WITH TA AT 11 O'CLOCK POS. STILL HAD RADAR DISPLAY ON; SO NOT AS CLR A DISPLAY OF TFC. ONLY ALT DIFFERENCE I SPECIFICALLY REMEMBER WAS 2500 FT ON CLBING TARGET. QUICKLY CHANGED TO RA AS TCASII ORDERED STOP OF DSCNT. TURNED OFF 'WX' AND SELECTED TCASII DISPLAY AND 10 MI SCALE. TCASII DIRECTED CLB. CAPT FLYING; COMPLIED WITH TCASII COMMANDS. CONFLICT QUICKLY RESOLVED DUE TO OUR CLB; TARGET PASSING 1-2 MI ABEAM; AND PROBABLE CORRECTIVE ACTION BY TARGET. ASKED APCH CTL IF HAD THE TFC AND ADVISED THAT WE HAD MADE TCASII DEV. APCH SEEMED UNCLR ABOUT TFC; THEN AFTER PAUSE; SAID IT WAS MTR FROM CARSWELL THAT HAD EXCEEDED CLRNC. CAPT WAS CONCERNED THAT MTR MIGHT BE MANEUVERING AND MIGHT BE IN CONFLICT AGAIN. I SWITCHED TCASII TO 30 MI RANGE TO CHK MTR BEHIND US. GOT APCH CTL TO CONFIRM THAT MTR WAS HDG W. APCH CTL SAID TFC CLR AND THANKED FOR OUR ACTIONS. WE NEVER SAW THE MTR. TCASII DID ITS JOB WELL. PROBABLY WOULDN'T HAVE HAD COLLISION WITHOUT IT; BUT COMMANDS ASSURED SEPARATION. APCH CTL OBVIOUSLY DIDN'T SEE THE CONFLICT UNTIL IT WAS ALREADY RESOLVED. THIS WAS VERY RAPID INCIDENT. FOR BEST ANALYSIS; 3 CHANGES OF FO DISPLAY WERE REQUIRED. SEPARATE GOOD SIZED TCASII DISPLAY WOULD MAKE ANALYSIS OF TFC CONFLICT MUCH EASIER WITHOUT MAKING MULTIPLE SELECTIONS. RADAR DISPLAY ALSO TENDS TO MASK AND CONFUSE TCASII DISPLAY.