QDC10 - Multiplex Data on Battery Power Lines

© 2002-2010 YAMAR Electronics Ltd.

2

DS-QDC10 R1.5

Shimon Hatarsi Tel Aviv, Israel. Tel (972) 3 5445294 Fax (972) 3 5445279

www.yamar.com

devices. The rest of the spectrum is reserved for higher speed channels and for multimedia

communication over the same DC power lines.

2.1.1

QDC10 Channel

The QDC10 channel is designed to operate over a single DC power line in the noisy conditions of a car.

Up to 16 devices can be connected on a DC line.

Center frequency F0:

1.79 MHz

Data transfer rate:

10 Kbps.

Cable length:

Up to 12m on DC cable.

2.2

QDC10 Device

The QDC10 device is responsible to receive and transfer messages to and from destination devices. A

message consists of 2 to 16 data bytes. The device handles the communication physical layer and part

of link layer (Modem, Channel coder, Carrier sense, Collision detection, and basic protocol).

The QDC10 device consists of a serial synchronous Host interface for communication with its Host,

Transmit and receive buffers, channel coder for error correction handling and a modem for line

communication. The device has special carrier detection logic and protocol handling logic. Figure 1.2

outlines the building blocks of the QDC10 device.

T o B a t t e r y P o w e r L i n e s

v i a p a s s i v e i n t e r f a c e n e t w o r k

C o m m a n d & D a t a

H o s t I / F

R e c e iv e

D a t a

B u f f e r

T r a n s m it

D a t a

B u f f e r

C h a n n e l

C o d e r / D e c o d e r

Q D C 1 0

T x / R x

H o s t In t e r f a c e

D e v i c e

t i m i n g a n d

P r o t o c o l

L o g i c

M o d e m

C a r r ie r

D e t e c t /

R e s o lv e

Figure 2.1 - QDC10 logical blocks

2.2.1

Device Ports

The QDC10 has the following ports:

Host Interface - A serial interface using 3 lines between the device and its Host micro-controller.

DC Line - Two lines for connection to and from the DC line interface or single wire bus.

2.2.2

Protocol

The communication is performed in messages. Each message starts with a header byte, followed by up

to 16 bytes of data. The device and its host coordinate message transmission, message reception,

entering Sleep mode and Wake-Up.. Higher level protocol (link and application layers) are under the

responsibility of the system designer.

2.2.3

Error Correction

Data is protected by an Error correction mechanism designed to meet impulse burst noises with

characteristic similar to those existing over the DC power lines.