Serial Communication

I am Reading data from a serial device, i have Frame Tracer which is connected to PC by USB.
I have Serial control of xojo to read data from tracer.

Its reading data but seems it is reading wrong data sometimes.
e.g. R2566;2568;2572;2576;2581;2585;2590;2595;2599;2604
It should be R=2566;2568;2572;2576;2581;2585;2590;2595;2599;2604 (misses ‘=’)

So am i missing any property of Serial control or something else?

You need to show your code in order for people here to help find possible problems with it.

The datareceived event doesn’t guarantee all data in one event. Also you may need 8-n-1 probably
That is 8 data bits, no parity, 1 stop bit.

If the data is expected with encoding, make sure you use defineEncoding