Real time properties of LANs according to the Manufacturing Automation Protocol (MAP)

The author reports on an evaluation of real-time properties of Manufacturing Automation Protocol (MAP) networks through analytical considerations which are then compared to measurement data. Measurements were made on a MAP 2.1 network that consists of 5 nodes based on the Motorola VME-bus MAP-controller MVME 372. This implementation has a complete logical link control layer (LLC-layer) and MAP-layer according to ISO 8802/8804 (with LLC-type 3 and priorities). Figures for message delay (for the MAC layer) and response time (for the transport layer) are given. Results for selecting protocol parameters affecting real-time behavior are given. Aspects for improved implementations of communication controllers for MAP networks are discussed.<
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