CTI Products IIB Console Interface - Manual (Page 11)

IIB Hardware Reference Theory of Operation
CTI Products, Inc.
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3.6 Parallel I/O Signals
The IIB provides two input/output lines per receiver (VOTE and DISABLE) that
allow both monitoring and control of the signal. Two output only lines per
receiver (FAIL and RECEIVE) are also provided. None of these I/O lines are
latched in the IIB. In the console, the VOTE switch or button should be
momentary, and the DISABLE switch or button should be latched.
Because the VOTE and DISABLE lines are input/output lines, when the VOTE or
DISABLE input is driven by the console, any device tied to that line will also be
driven (an LED for example).
3.7 Bi-directional Lines
Because the console VOTE and DISABLE lines are bi-directional, the console’s
LEDs will be lit if the console outputs are active. Because of this, the console
could still indicate a DISABLE or VOTE on a receiver even if there is a problem
in the network cabling or the Comparator I/O Module.
This is one reason for using the Link Failure Reporting of the IIB (see section 7.1,
Link Failure Reporting). Using this feature, the operator can be warned when the
comparator is not communicating with the Comparator I/O Module (provided the
Comparator I/O Module supports Link Fail reporting) or when the IIB is not
communicating with the Comparator I/O Module.