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PLM-1 Transceiver: Introduction |
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Abstract: The AC-PLM-1 transceiver is a digital Integrated Circuit (IC) implementing a half-duplex transmitter/receiver function at the physical layer of Power Line Communications (PLC) network.
The AC-PLM-1 transceiver is a digital Integrated Circuit (IC) implementing a half-duplex transmitter/receiver function for Power Line Communications (PLC). The IC includes a complete set of high-level functions, enabling designers to easily implement high-performance PLC networks. The PLM-1 offers the following features:
- Data Coding and Formatting : The chip automatically formats packets and encodes/decodes user data.
- Medium Access: The chip implements a CSMA/CD algorithm, and resolves medium contention.
- Prioritization: The chip supports three priority levels and transmits higher priority messages first.
- Transaction: The chip supports "Unacknowledged" and "Acknowledged" transactions.
- Timer Function: The chip includes a programmable eight-bit timer.
- Protocols: The chip is protocol-neutral and can transport any protocol packet. Using protocol identification data, the chip can transport two or more protocols in a single network, and even for a unique application.
The PLM-1 is, in substance, a general data-transportation mean that solves all network implementation problems. Transmission, for example, is simple: data is loaded into the IC and the PLM-1 automatically waits for the channel (medium) to be idle, calculates the message priority level (so as to let higher priority messages go through), detects and resolves medium contention, emits synchronizing characters, adds Forward Error Correction bits, calculates a Cyclic Redundancy Check word, transmits the encoded packet data, and finally appends the calculated CRC. The application micro-controller (host) simply feeds the PLM-1 IC with packet data, and the PLM-1 IC automatically takes care of networking functions.
Receiving is just as simple: the receiver automatically performs the opposite functions to pass the packet data or any received error to the host.
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