how to interpret the serial data

is it posible to use two start and end maker...

Yes, but...

<jvvmv,fff> is easier to deal with. Save all the data, then use strtok() to parse into jvvmv and fff.

With two start and end markers, you need two arrays, and you need to keep track of which array to store a character in. Does f go in the first buffer or the second buffer?