Uart made problems


I use 3 UART’s.
I have connect a RS485 Converter to UART 4.
On the RS485 is a SmartMeter with ModBus Communication.

I send a request to this Smartmeter and he answer with the data.
On my PC I tested and all is fine (157 Bytes each answer)

But when I try this on the BeagleBone Black, I just receive 125 - 127 Bytes.

How can i check if my serial Port on the BBB is 9600 8N1?

stty -F /dev/ttyO4:
speed 9600 baud; line = 0;
min = 0; time = 5;
-brkint -icrnl -imaxbel
-opost -onlcr
-isig -icanon -iexten -echo -echoe -echok -echoctl -echoke

Are this settings correct?

Or has someone an idea for this problem?

Thank you!

(btw: I check and send from the PC over RS232 some ASCII to the BBB. All are fine)