Questions and Answers

The BRM1553 and other IP-Cores are provided with an API (set of functions) for Windows and Linux, written in native C and compiled with GCC compiler. The release includes drivers for Windows only and API source code that can be compiled to other Operating Systems like Integrity (some modifications might be required by the user).
Sital also provides commercial VxWorks drivers for the BRM1553 IP core and various Interface cards. These drivers are provided under license; please contact us for more details.


In Mil-Std-1553, BC does not contain a sub-address, so there is no need to set it up in COMposer. Any settings will be ignored.

COMposer runs on WinXP, Win7-32/64bits, Win8/8.1-32/64bits and Windows 10 32/64 bits

To enable the TDR data view in Buffalo software, click the TDR button on the right-hand side of the Bus Monitor window in the Buffalo software (visible only when running in Engineering mode).
The TDR data will be displayed for each module in the bus topology showing the current reflection value in nanoseconds.
These TDR numbers, whether positive or negative, represent the distortion from the normal CAN bus pulse width (2000ns) as measured per ECU.
For example, if 2010ns was measured, then 10 will be displayed; if 1990ns was measured then -10 will be displayed.
Without any wire faults, these numbers are the reference base (“ok” value). When there is a fault, the TDR numbers minus the reference base provide the distance to the fault in ns.  The estimated value per meter is 11ns for double wire disconnect.
When clicking on a module (while in TDR mode), a popup dialog with the “ok” value, current and peak values and difference from the “ok” value is displayed.
For single wire disconnection the TDR values are less accurate, because the signals are highly distorted.

Sital tools, Buffalo and SpyTDR, transmit standard CAN frames for a number of other practical reasons (reading DTCs, communicating with non-flashed modules, etc..), but the pTDR technique itself is completely passive.

Time-domain reflectometry or TDR is the ability to measure the distance to an electrical line fault based on reflections.
TDR analysis begins with the propagation of an energy impulse into the system and the subsequent observation of the energy reflected by the system.
When using TDR in a serial communication bus like a CAN bus, if the bus is intact, there are no reflections and all the energy turns to heat on the terminators.
In the case of a wire fault, there are reflections, whose delay depends on the propagation speed in the wires and the distance they traveled.
Sital’s off-the-shelf TDR tool transmits a pulse to the line, and measures the time to its reflection to estimate the distance in nanoseconds (ns) to the fault location.

Passive-TDR (pTDR)
Sital’s Passive TDR (pTDR) technology can estimate the distance to the wire fault without transmitting any signal to the bus!
pTDR derives the required information from the ongoing communications on the line without disturbing the ongoing bus activity.
When there is a bus disconnection, the reflections (from the ongoing signals) distort the communication signals and change their pulse width.
Measuring the distortion of a pulse width from its standard value provides the TDR information.
Passive TDR is the only TDR technique which does not send any signal to the bus (therefore it is called passive).
pTDR is being used to detect and locate wire faults such as disconnection and shorts.
Being able to run on live wires enables this technology to accurately detect and locate intermittent faults.