Sital Technology Ltd. announced today that its patented technology for detecting wiring faults will be integrated into its BRM1553D, BRM1553FE and BRM1553PCI Mil-Std-1553 IP cores and boards.
Sital’s Passive TDR (pTDR™) technology is capable of detecting wiring problems such as disconnections, short-circuits, and others, whether they are constant or intermittent. pTDR is a Passive Time Domain Reflectometer (TDR) technology, which constantly measures reflections of energy on an operating Mil-Std-1553, CAN or similar bus. pTDR technology runs during normal system operation without disturbing the standard bus activity.
A standard TDR device sends pulses of energy to the bus and measures the reflected signal. Reflections are created from wiring faults such as disconnections, shorts or lack of proper termination. The time it takes for the signal to travel to the fault and back to the TDR is related to the location of the fault. However, a TDR cannot run while the system is operating, simply because it would be confused by the on-going transmissions on the bus, and also because it may disturb the standard communication.
pTDR does not transmit any pulses to the bus. Instead, it monitors the existing communications and measures reflections created by the normal transmissions. If there are wiring faults then signals will be distorted in certain ways that are related to the location of the fault. The main distortion is related to the width of transmitted bits. For example, in Mil-Std-1553 bits width is 1uS. A distorted bit can last for an additional few nano-seconds, according to the location of the fault. pTDR measures the distortions and reports the additional length of each bit. We call this additional length a “tail”.
The Sital pTDR system constantly reports tails from all Remote Terminals (RTs) on the network. In a correctly performing bus the tails from all RTs will be small and uniform. Changes in the tails indicate a bus fault.
Tail measurements are constantly performed on every message and updated on every frame. Therefore, even a very short disconnection event will be reported.
“The current situation is that each system on the aircraft performs its own built-in-test (BIT) and reports its own problems. But there is no mechanism for performing BIT to the bus wires or reporting wiring problems when they occur.” said Ofer Hofman, Sital’s CTO. “Our technology adds a great level of reliability to the bus, without interfering with the bus activity and without adding any complexity to the system.” He added.
Duli Yariv, Sital’s VP Marketing and Sales said: “Our pTDR™ technology is already implemented on CAN bus and used by automotive manufacturers for detecting wiring faults on vehicles during manufacturing, maintenance and operation. We are excited to enable our avionics and automotive customers to enjoy this technology, add value to their products and make safer aircraft and vehicles.”
pTDR technology for detecting wire faults will be available on the full range of Sital products: testers, IP cores and interface boards.
For more information please visit: http://sitaltech.com/technology/smart-wiring-fault-detection-technology/