#transport protocol

The Two Elements of the SAE J1939 Protocol Stack

Any SAE J1939 hardware must support SAE J1939/1x and SAE J1939/21; otherwise, they’re useless because these standards describe the CAN bus physical layer and the basic protocol features.

A fully functional SAE J1939 protocol software must support one mandatory element, SAE J1939/81 (address claim process), and, if needed, SAE J1939/21 (transport of up to 1785 bytes per message).

SAE J1939 Transport Protocol (TP) Functions

Even though extremely useful in passenger cars and small industrial applications, CAN alone was not suitable to meet the requirements of truck and bus communications, mainly since its communication between devices is limited to only 8 bytes per message. However, it is possible to extend the size of a CAN message by implementing additional software, i.e., so-called higher layer protocols. J1939 is such a higher-layer protocol, and it supports up to 1785 bytes per message.

Slovakia to Send its First Ever Satellite Into Space:

April 11, 2016 at 09:08PM

http://ift.tt/1qFljsl Slovakia is gearing up to launch its first satellite to orbit with the aim of demonstrating the country’s ability to carry out scientific experiments in space. The pocket-sized one-unit CubeSat, named skCUBE, is currently slated for liftoff in June atop SpaceX’s Falcon 9 rocket from the Cape Canaveral Air Force Station in Florida. The central…