CTI Products MCN Server 8000 - Manual (Page 175)

Advanced Configuration Configuring Master-Sub Comparator Systems
175 68-12286-110
Bit Mask and Nudge Fields
The Bit Mask fields indicate which bit(s) is (are) used to pass to the SubDevice.
In general, the "Nudge" field should be the number of native bits in the destination SubDevice Table. (If
there are Multi-dependencies – multiple Master Comparators for each Sub Comparator – you will need
to specify special nudge values.)
Master Bits Steer Rx Dis Vote Fail
Mask 0 0 0 1 0
Masked Vote
Compressed
& Shifted Vote
Nudged (5) Master
Vote
Sub
Comparator
Bits Master
Vote
(Inherited)
Steer Rx Dis Vote Fail
The best way to understand how to set the Bit Mask and Nudge fields is to consider how the MCNRCD
program processes the bits from the Master comparator as shown above:
1. The program masks out all bits that have a "0" in the mask field.
It passes only those bits that have a "1" in the Bit Mask field (Vote in this case)
2. All the bits with a "1" in the bit mask field are compressed and shifted to the right to fill the Least
Significant Bits (right hand bits). In the above example, there is no compression going on – only
shifting. The compression comes in when there are multiple non-contiguous mask bits set to "1". In
that case, the program compresses the bit field by deleting all the unused bits. This is shown in the
Multi-Bit Mask section on the next page.
3. The Compressed & Shifted Bits will be nudged to the left by the number specified in the "Nudge"
field (5 in this case).
4. The Nudged bit will be passed to all the receivers in the Sub Comparators.
5. The resultant bits (the inherited bit plus the "native" Sub Comparator bits) will be used in the Sub
Comparator Display Table to determine the status to display.
Inherited bit "Native" bits from Sub Comparator CIB