Connecting teltonika rut 955 on rs 485

HELLO,
IM HAVING SOME ISSUES TO CONNECT TELTONIKA RUT 955 IN PORT 485, TO UNITRONICS V280 ON PORT 485.
I WANT TO USE THE TELTONIKA TO PROGRAM THE UNITRONICS CONTROLLER.
I FOLLOWED ALL DEFINITIONS,
AND WHEN I PRESS GET OPLC IN UNITRONICS I MANAGE TO GET THE INFORMATION BUT I CANT DOWNLOAD TO THE CONTROLLER.
THANKS FOR YOUR HELP.