Sound during servoj loop

Technical Questions Robot Communication
1

When I sent the following small program to the robot using the real-time client interface, the robot starts emitting a continuous tooting sound as long as the program is running:

def standstill():
    current_angles = get_actual_joint_positions()
    while (True):
        servoj(current_angles, 0, 0, t=0.002, lookahead_time=0.100, gain=200)
        sync()
    end  # end of while loop
end  # end of function

The sound is approximately like a deep sine tone, similar to television idle signal.

Why is it making that sound, and is it expected?

2

It seems like this is a consequence of sending servoj commands with way too short time horizons (i.e., values of t near or below the length of a single frame). When I increase the value of t so that this time horizon easily overlaps several frames (e.g., 0.2 instead of 0.002), then there is no sound.