save data with automatically stop

[takimidante]

Hello 2 everyone.firstly i hav no problem bout how to build a waveform from the string using RS232 serial comm.I'm using instrument I/O assistant (IIOA) to communicate with message-based my hardware and graphically parse the response.The list of numbers below shown from ASCII of my microcontroller. After I configure my hardware using IIOA, i can build the string V n I easily.so,my problem is how to write to measurement file and save into one file with timer.Such a example like...emm... let's say if I want to start save data into file form now.and then i want to stop in 3 minutes later without controlled by me.so it will be automatically stop in 3 minutes...like a timer.so now, i'm using a function like write to measurement file to save data. n I don't think that this is the best way.or maybe I'm wrong.so..I hope you guys can help me to fix this prob .here, i attach the files to anyone n i hope that you all can fix me the prob of this.thank u......

V= 2, I = 4

V= 3, I = 5

V= 4, I = 6

V= 5, I = 7

V= 6, I = 8

V= 7, I = 9

V= 8, I = 10

V= 6, I = 8

V= 7, I = 9

V= 8, I = 10

V= 9, I = 11

V= 10, I = 12

V= 2, I = 4

V= 3, I = 5

V= 4, I = 6

V= 5, I = 7

V= 6, I = 8

V= 7, I = 9

V= 8, I = 10

V= 9, I = 11

V= 10, I = 12