Hi,

I'm devolping a tool to automatically test a 1553 device, but I did't understand what means the "zero crossing distortion" test. Could I have more information?

Thanks!

The zero crossing distortion test is part of the "RT Validation Test Plan". This is available in the MIL-HDBK-1553A (available as a free PDF file). The latest version of the test plan is available from the SAE in the AS4111 document (costs about $60).

The relevant test is paragraph 5.1.2.1.1 (zero crossing distortion). Basically, you must test each zero-crossing in the command word and data word of a receive message by injecting positive and negative shifts in the zero crossing of +/- 150 nanoseconds - the RT should not see this as an error and should respond with clear status.

I have written a program that performs the zero crossing distortion test using the Alta Data Technologies 1553 boards (www.altadt.com). The "AltaRTVal" software implements all the protocol tests (5.2) of the AS4111 RT Validation Test Plan.

Rich Wade