Practical TCP/IP and Ethernet Networking- P61: The transmitter encodes the information into a suitable form to be transmitted over the communications channel. The communications channel moves this signal as electromagnetic energy from the source to one or more destination receivers. The channel may convert this energy from one form to another, such as electrical to optical signals, whilst maintaining the integrity of the information so the recipient can understand the message sent by the transmitter | 282 Practical TCP IP and Ethernet networking M m Meter. Metric system unit for length. M Mega. Metric system prefix for 106. MAC Media Access Control IEEE 802 . Manchester encoding Digital technique specified for the IEEE Ethernet baseband network standard in which each bit period is divided into two complementary halves a negative to positive voltage transition in the middle of the bit period designates a binary 1 whilst a positive to negative transition represents a 0 . The encoding technique also allows the receiving device to recover the transmitted clock from the incoming data stream self clocking . MAP Standard profile for manufacturing developed by MAP. MAP Manufacturing Automation Protocol. A suite of network protocols originated by General Motors which follow the seven layers of the OSI model. A reduced implementation is referred to as a mini-MAP. Mark This is equivalent to a binary 1. MAU Media Access Unit. MAU Multistation Access Unit. Media access unit This is the Ethernet transceiver unit situated on the coaxial cable that then connects to the terminal with a drop cable. Microwave AC signals having frequencies of 1 GHz or more. MIPS Million Instructions Per Second. MMS Manufacturing Message Services. A protocol entity forming part of the application layer. It is intended for use specifically in the manufacturing or process control industry. It enables a supervisory computer to control the operation of a distributed community of computer-based devices. MODEM MODulator-DEModulator. A device used to convert serial digital data from a transmitting terminal to a signal suitable for transmission over a telephone channel or to reconvert the transmitted signal to serial digital data for the receiving terminal. AppendixA Glossary 283 MOS Metal Oxide Semiconductor. MOV Metal Oxide Varistor. MTBF Mean Time Between Failures. MTTR Mean Time To Repair. Multidrop A single communication line or bus used to connect three or more points. Multiplexer MUX A .
