Conditions for ProtocolError and SystemError Error Bits of BTI1553LV.lvlib: Get Error Fields Cluster.vi

Issue Details

In BTI1553LV.lvlib: Get Error Fields Cluster.vi, under what conditions are the ProtocolError and SystemError bits set?

Solution

ProtocolError (MSGERR1553_PROTOCOL)
This bit is not used by the OmniBus II protocol engine on this board. It is reserved for use in other products and does not indicate any actual error condition in this implementation.

SystemError (MSGERR1553_SYSTEM)
This bit is set when the protocol engine detects an issue while validating its own transmitted data. The OmniBus II protocol engine performs the following internal process:

• It decodes its own transmitted MIL-STD-1553 signal
• Compares the decoded data against the expected transmitted values
• Flags an error if a mismatch is detected

Examples of conditions that trigger SystemError:

• Timing issues (bit or word timing misalignment)
• Word value mismatches
• Encoding errors (e.g., Manchester encoding inconsistencies)Any discrepancy between transmitted and internally decoded data

Additional Information

• The SystemError bit does not indicate a receive-side bus error, but rather an internal self-check failure of transmitted data.
• External factors such as wiring issues, improper termination, or poor signal integrity can indirectly lead to this error, as they may cause discrepancies during internal decoding.