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@ 2007 Yamar Electronics Ltd.

2

DS-SIG40 R1.8

2

OVERVIEW

2.1

Signaling System

The SIG40 device is based on a patented Signaling technology. The device transmits and receives a

special signaling carrier, which can be differentiated from noise. The receiver receives the signaling

patterns, extracting them into the original bits. The rest of the spectrum is reserved for additional

communication channels over the same DC noisy lines.

2.2

Channels and Network

The SIG40 operates over one of two preset selectable channels (frequencies) using a single line such

as the vehicle's battery power line. Up to 16 devices can be connected to each of the channels over the

same line. Each of them can broadcast asynchronous data messages to other devices on the bus

according to the LIN protocol. The device is controlled by its host microprocessor through its UART.

Channel frequencies:

3.58MHz to 6.5MHz

Data transfer rate:

19.2Kbps to 57.6Kbps.

Cable length:

See 3.3.9.

2.3

The SIG40 Device

The SIG40 device is responsible to transfer messages to all devices over the line. The device handles

the communication physical layer and Interference detection. The device communicates with its host via

an asynchronous serial port for data transfer and device control. Figure 2.1 outlines the building blocks

of the SIG40 device.

T o / F r o m L i n e i n t e r f a c e

H o s t I / F

S ig n a li n g

G e n e r a t o r a n d

D e t e c t o r

S I G 4 0

H o s t I n t e r f a c e

M o d e m

T im in g

& S y n c h

P L L

P r o t o c o l

H a n d l e r

I n t e r f e r e n c e

D e t e c t o r

P r o t o c o l

C o n t r o l l e r

3 2 K

O s c illa t o r

S le e p

C o n t r o l

Figure 2.1 - SIG40 logical blocks

2.4

Protocol

The LIN protocol is based on a master device communicating with up to 15 slaves using half-duplex

UART data. The device is transparent to the LIN host while providing additional services for the link and

application layers with a built-in Interference detector and frequency management.

2.5

Power Management

Sleep Mode, controlled by the host, saves power by disabling most of the circuits.

During Sleep Mode, the device is switched On for a short period to detect wakeup messages from other

devices on the bus. If no activity is detected, the device is switched back to Sleep.