DPN – CAN Bus Technology Comparison

DPN-BUS PROTOCOL compared to SAE J1939 CAN-BUS PROTOCOL

CHARACTERISTIC DPN-BUS PROTOCOL SAE J1939 CAN-BUS PROTOCOL
Utilization of Wires Wiring carries both differential communication signal and 12V or 24V DC power. Wiring carries differential communication signal only.
Configuration of Wiring Non-twisted wiring possible when spacing from other wiring is controlled by jacketing or other methods. Twisted pair may be necessary with uncontrolled spacing if application requires extremely low levels of radiated emissions. Unshielded twisted pair per J1939-15.
Topology of Wiring Linear wiring structure with built-in terminations for standard systems with up to eight modules. Linear wiring structure with a termination at both backbone ends. Supports up to ten modules per J1939-15.
Utilization of Frequency Spectrum Modulated radio frequency carrier uses frequencies from 4.45 to 4.55 MHz with a 6.5 MHz option. Baseband signaling uses frequencies from 0 Hz to 1 MHz at 250K bits/sec with the preferred rise and fall times in J1939-15.
Method of Encoding Data Information is conveyed by series of phase changes with typical amplitude of 250mVrms at transmitter and a range of 10mV to 250mV at the receiver. Information is conveyed by changes of signal amplitude with typical values of 2V at transmitter and 1.2V at the receiver.
Structure of Network Intercommunication Peer-to-peer using time division multiplexing. Peer-to-peer using lossless bitwise arbitration.
Detection of Data Errors Cyclic redundancy check of data plus multiple symbol error checking of modulated signal. Cyclic redundancy check of data.
Delay Time of Data Maximum Gateway message forwarding delay is 48mS in an eight module system and 12mS in a two module system. Meets J1939-31 section 6.2.1 recommended maximum value of 50mS for CAN Gateways.