manufacturing automation protocol (OSI) (MAP)
The Manufacturing Automation Protocol(MAP) was an implementation of OSI-compliant protocols in automation technology initiated by General Motors in 1984. MAP became a LAN standardization proposal supported by many manufacturers and was essentially used in factory automation.
The MAP specification 2.1 was based on the OSI reference model for open systems and the corresponding protocols. MAP 2.1 used a wideband system with a transmission rate of 10 Mbit/s in a 12 MHz frequency range(75 Ohmcoaxial cable, modulation: Multilevel Duobinary AM/ PSK).
The broadband system complied with IEEE 802.4 for the token bus. MAP allowed the construction of complex communication infrastructures using bridges, gateways and routers. Broadband components such as junctions, amplifiers and equalizers allowed networks to be structured at the physical level. The MAP 3.0 specifications have been in existence since 1987. Here, Ethernet networks of the type IEEE 802.3 were rather used, since they had established themselves in the meantime in the manufacturing environment by improved designs. European MAP interested parties had organized themselves in the European MAP User Group (EMUG).