Communications system of two-wire line enhancing fail-safe performance
AssigneeDenso Corporation
InventorsTakeshi Suganuma, Yoshimitsu Fujii
Life of this patent
Estimating the term…
Abstract
Five ECUs control vehicle devices using CAN protocol. Each of ECUs is provided with a resistor and a switch for activating the resistor. A first and fifth ECUs are arranged on the leftmost and rightmost ends. Resistors of the first and fifth ECUs are used as terminating resistors to a two-wire communications line. When the two-wire communications line is broken, the first ECU sends a test signal while other ECUs excluding the fifth ECU turn on the switches from right to left. When the test signal can be received, a broken point is located on the right side of ECU that turns on its switch at that time. Thereafter ECUs on the left side of the broken point conduct communication.
Claims6
A communications system in which a plurality of communications devices conduct communication via a two-wire communications line having terminating resistors connected to its both ends, the communications system comprising:
- a standby resistor corresponding to each of at least one of the communications devices connected to the two-wire communications line, wherein the standby resistor can be one of the terminating resistors;
- and
- communication restoring means that when a break failure occurs in the two-wire communications line, locates a failed point of the two-wire communications line and connects the standby resistor corresponding to a given communications device, which is included in the communications devices and arranged near the located failed point, as one of the terminating resistors to the two-wire communications line thereby to enable a certain part of the communications devices to conduct communication, wherein the certain part of the communication devices that include the given communications device are arranged opposite to the failed point when viewed from the given communications device.
Dependencies are inferred from the claim text.