DC BUS technology enables network power line communication of Data, Voice, Music and Video by digital means over Direct Current (DC) battery power lines, like those used in every vehicle.
Yamar’s unique technology enables advanced digital communication in hostile and noisy environments such as on vehicle battery lines in a small size silicon device. Customers integrate the devices into modules utilizing their own application (e.g. within body and power train modules for in-vehicle multiplex communication networks). The DC-BUS is used in many non automotive applications too.
The same power line can be used for multiple independent networks by using different carrier frequencies.
The cable length depends mainly on an impedance @5MHz of loads connected to the power line. A 10A motor is a small load, but a filtering capacitor of 10nF is a high load.
The SIG60 has selectable carrier frequencies in the range of 4.5-13MHz and its output level is ~1.2Vpp. The SIG60 can receive a signal as low as 20mVpp. A reasonable distance is between 20m to 100m. When connected by a short distance from the battery, the communication distance will reduce further.
For more application specific information, you can contact our support team.
There is no physical limitation for the number of nodes, but in practice 16-32 nodes is a reasonable number.
The SIG60 device operates up to 115.2Kbps. The DCB1M operates up to 1.4Mbps.
The SIG60 transfers UART bytes over the power line. It gets a byte and transfers it over the power line with a latency of ~3.5 bits. Any number of bytes can be transferred. The modulation is multiple phase modulation. When operating as a network, a master-slave protocol such as LIN can be used. Semiconductor devices are in full production.
The DCB1M is a message oriented device. It gets a message of any length and transfers it over the power line to the receiving devices. The DCB1M has arbitration CSMA/CR mechanism for network operation. The interface with its ECU via UART or SPI protocol interfaces.
Yes. Two or more data buses can operate over the same power line using different carrier frequencies. The SIG60 has 7 selectable carriers.
We recommended that a “software” separator is added into the user’s protocol to avoid any leakage from one strong transmitter to another sensitive receiver using a different carrier, and vice versa.
The DC-BUS was designed to operate on ordinary wires. Using low capacitance wire such as twisted pair cables, UTP, improve the effective communication length and performance.
The communication is not affected by the diode bridge because the carrier signal level is less than 1.4Vpp and it passes through the diode bridge.
The Multiphase modulation is a unique type of PSK modulation developed by Yamar. It is based on multiple combinations of phases and provides excellent performance even when the communication channel is noisy.
The SIG60 schematic in Figure 3.3 is recommended. Don’t forget to add an inductor >22uH to your power supply before connecting it to the power line. The inductor is needed to ensure that the power supply filtering capacitor will not short the carrier signal.
Yes. Adding a coupling capacitor between the two power lines will enable communication between the SIG60 devices.
When the HDC pin is low, the HDI and HDO pins communicate with the internal registers. The SIG60 detects the uC bit rate (9.6Kbps, 19.2, 38,4, 57.6, and 115Kbps). After lowering the HDC pin, send the Read or Write command via the uC serial port as described in the data sheet.
It is important to wait until the uC finishes transferring its data bytes to the SIG60 (depending on the UART bit-rate) before raising the HDC pin. With the Read command, the SIG60 responds immediately (<1uS) after the end of the command. Check the SIG60 datasheet, at the SIG60 page or in the support page under the Datasheet section.
The easiest way is to use the message generator that Yamar supplies or, use the format as described in the SIG61 data sheet (can be found in the support page under the datasheet section).
Using discrete filters does not reduce the communication performance, because the attenuation of a discrete filter is only 3db while a ceramic filter attenuation may go to 6db. However, if several carriers are used for different power line networks, some cross talk may occur.
Yamar supplied USB driver will operate after allowing unsigned driver installation. Go to the link below and use option two: “Use an Advanced Boot Option”
Make sure the USB board is connected to the SIG60 EVB and the EVB is powered..