55xGenComm1_29
12
Sentinel values for instrumentation
The instrumentation items (GenComm pages 4,6 and 7) may return the sentinel values described
in the table below. These are used to indicate special conditions measured by the control module.
The sentinel value ‘high digital input’ means that the instrumentation value is high (high oil
pressure, high temp, etc), similarly 'Low digital input' means the instrumentation value is low. They
do not refer to voltage levels on the inputs.
Size of register Sentinel values Notes
16 bit unsigned, any scale 0xFFFF Unimplemented
0xFFFE Over measurable range
0xFFFD Under measurable range
0xFFFC Transducer fault
0xFFFB Bad data
0xFFFA High digital input
0xFFF9 Low digital input
0xFFF8 Reserved
16 bit signed, any scale 0x7FFF Unimplemented
0x7FFE Over measurable range
0x7FFD Under measurable range
0x7FFC Transducer fault
0x7FFB Bad data
0x7FFA High digital input
0x7FF9 Low digital input
0x7FF8 Reserved
32 bit unsigned, any scale 0xFFFFFFFF Unimplemented
0xFFFFFFFE Over measurable range
0xFFFFFFFD Under measurable range
0xFFFFFFFC Transducer fault
0xFFFFFFFB Bad data
0xFFFFFFFA High digital input
0xFFFFFFF9 Low digital input
0xFFFFFFF8 Reserved
32 bit signed, any scale 0x7FFFFFFF Unimplemented
0x7FFFFFFE Over measurable range
0x7FFFFFFD Under measurable range
0x7FFFFFFC Transducer fault
0x7FFFFFFB Bad data
0x7FFFFFFA High digital input
0x7FFFFFF9 Low digital input
0x7FFFFFF8 Reserved