The ornamental design for a datatransmissiondevice, as shown and described.
FIG. 1 is a front, top and right side perspective view of a data transmission device showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a left side view thereof;
FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 2; and,
FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 4.
The broken lines illustrate portions of a data communication device and form no part of the claimed design. The dash-dot lines define the bounds of the claim and form no part of the claimed design.