Using the portal, you can send an SMS message from several areas of the portal: The dashboard, the SMS Messaging interface, or from 2D and 3D maps. The compose options vary for each area. Messages can be sent to any vehicle or group of vehicles with valid phone/SMS number. If your account assigns drivers to vehicles, you can instead choose from individual drivers or a group of drivers. Messages will be sent from the 477-477 (GPSGPS) number. Messages cannot exceed 160 characters.
Although the portal interface has been updated since this video was recorded, the process has not changed.