robot articulation(motor) angle

You didn't specify where you wanted this done. But yes...

... if you meant the mechanism model in RobotStudio then in the [Layout] browser, right click the mechanism and in the context menu select [Mechanism Joint Jog] .

Then you can, by joint, either drag the bar, or, with a joint selected use the number keys to enter a specific number of degrees.

...if you instead meant during motion then the RAPID command you are looking for is MoveAbsJ

http://developercenter.robotstudio.com:80/Index.aspx?DevCenter=DevCenterManualStore&OpenDocument&Url=../RapidIFDTechRefManual/doc93.html

like this:

MODULE Module1

     CONST jointtarget JointTarget_1:=[[5,10,15,20,25,30],[9E9,9E9,9E9,9E9,9E9,9E9]];

    PROC Path_10()

        MoveAbsJ JointTarget_1,v1000,z100,tool0\WObj:=wobj0;

    ENDPROC

If you meant in some other context then please specify further.