Digi M10 manual Types of Communication Methods, Data Reports, Messages, Global Grams

Digi m10 Technical Overview v 1.20

2. Types of Communication Methods

2.1Data Reports

A Data Report is the basic service element the Digi m10 uses to transmit or receive a single packet containing 6 bytes or less of user-defined data. A Data Report can require an acknowledgment of successful delivery to the ORBCOMM Gateway, but this acknowledgment can be omitted to save space segment resources. A Data Report can only use speed dials to indicate where the message should be delivered.

More documentation can be found on the CD provided with the JumpStart Kit. To learn more, please refer to corresponding sections in the ORBCOMM Serial Interface Specification document.

2.2Messages

A Message is the basic service element the Digi m10 uses to transmit or receive a longer sequence of data. To ensure reliability, messages are transferred over the satellite reservation channels via short packets containing a checksum, with all packets acknowledged or retransmitted. Messages must fit within a 1024-byte packet. Messages can either use a speed dial to indicate the message delivery destination or an e-mail address.

2.3Global Grams

A GlobalGram is the basic service element the Digi m10 uses to transmit or receive a single, self- contained data packet to or from a satellite that is not currently in view of an

ORBCOMM Gateway. This allows remote and oceanic areas to be served in a “store-and- forward” mode. For an SC-Terminated GlobalGram, the relaying satellite stores the data packet in memory and transmits it upon request from the destination Digi m10. An SC-Terminated GlobalGram contains 182 bytes of user data. For an SC-Originated GlobalGram, the satellite receives the GlobalGram from the Digi m10, acknowledges it and archives it in satellite memory until the destination ORBCOMM Gateway establishes contact with the satellite. An SC-Originated GlobalGram contains 229 bytes of user data. A Global Gram can only use speed dials to indicate where the message should be delivered.

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