Date: 29/05/2012

CAN eye-diagram mask testing introduced by Agilent on its InfiniiVision scopes

Agilent Technologies Inc. has introduced the oscilloscope eye-diagram mask testing capability for the differential controller area network serial bus. The CAN serial bus is used for control and sensor monitoring in automotive applications as well as industrial and medical equipment applications.
Oscilloscopes are the measurement tools used to verify the signal integrity of the CAN bus physical layer. The new CAN eye-diagram mask test capability in Agilent's 3000 X-Series oscilloscopes can perform a composite signal-integrity measurement of their CAN buses in one easy measurement.

Eye-diagram mask testing is one of the ways designers can measure the overall signal quality of their serial bus networks. The CAN eye-diagram test randomly captures and overlays every differential bit of every CAN frame based on a unique clock-recovery algorithm that emulates worst-case CAN receiver hard synchronization, resynchronization and sampling. The result is a single measurement that provides insight into the overall signal integrity of the CAN's physical layer to show worst-case timing and worst-case vertical amplitude variations. Overlaid bits are then continually compared against a six-point polygon-shaped pass/fail mask limit, which is based on CAN physical-layer specifications.

Physical delays cause the timing uncertainty in the asynchronous event-driven architecture of controller area networks (CAN). The longer the Controller Area Network, the longer the delays. Agilent's new CAN eye-diagram mask testing capability detects and shows these worst-case network delays.

The DSOX3AUTO CAN/LIN trigger and decode option and the DSOX3MASK mask-test option (both are required for CAN eye-diagram mask testing) are priced at $729 each. The entry-level price of an Agilent InfiniiVision 3000 X-Series oscilloscope with these options is $4,324. Customers who already own an Agilent 3000 X-Series oscilloscope with the DSOX3AUTO and DSOX3MASK options can upgrade their scopes with the latest firmware to enable CAN eye-diagram mask testing at no charge.

Agilent also provides specific mask-test files based on differential probing polarity, baud rate and network length. These mask-test files can be downloaded at no charge.
Information about the DSOX3AUTO option is available at www.agilent.com/find/scopes-auto