Frequently Asked Questions
What is the DC-BUS Power Line Communication Technology?
DC BUS technology enables network power line communication of Data, Voice, Music and Video signals by digital means over Direct Current (DC) battery power lines, like those used in every vehicle. Yamar’s unique design 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 same power line can be used for multiple independent networks by using different carrier frequencies.
What is the maximum cable length for communication over the DC power line?
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.
How many DC-BUS nodes can be connected over the power line?
There is no physical limitation for the number of nodes, but in practice 16-32 nodes is a reasonable number.
What is the maximal bit-rate of Yamar's devices?
The SIG60 device operates up to 115.2Kbps. The DCB1M operates up to 1.3Mbps.
What is the difference between the SIG60 and the DCB1M?
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 DC-BUS message oriented device. It gets a message of any length and transfers it over the power line to the receiving devices. The DCB1M has CSMA/CR mechanism for network operation. The interface with its uC is via UART or SPI protocols. The DCB1M is currently available as FPGA evaluation board.
Is it possible to operate two or more independent DC-BUS networks on the same powerline?
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.
What is the effect of different types of cables on the communication performance?
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.
Is it possible to add a polarity protection diode bridge before the DC line input? How does the diode bridge affect the communication?
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.
What is the Multiphase Modem that is implemented in the SIG60 semiconductors?
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.
Can I use the SIG60 schematic in the data sheet Fig 3.3 as a reference for the design of my application?
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.
Is it possible for two SIG60 devices that are connected on different power lines to communicate with each other? (i.e.12V and 24V)
Yes. Adding a coupling capacitor between the two power lines will enable communication between the SIG60 devices.
How can I control the SIG60 internal registers from a Micro-controller?
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.
How do I generate a UART message to operate the SIG61 slave device?
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).
How is the communication performance affected when using a discrete filter instead of the ceramic filter?
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.
How To Install The SIG60 USB Interface Driver On Win8 and Win10 platform?
Priro to Driver Installation please refer to the following link : http://www.nextofwindows.com/how-to-install-an-un-signed-3rd-partydriver-in-windows-8/.