User`s guide

Release E UMC800 Control Builder User’s Guide 223
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Appendix A - Logic Application Examples
Overview
Introduction
The controller offers up to 66 digital inputs or outputs and uses digital function blocks to perform logic
operations and sequences.
• The UMC800 logic function blocks will replace from 40 to 60 rungs of ladder logic on the average (for
straight combinations or Boolean functions, timing and counting) assuming an average of 6 logic
functions per rung consuming 3-4 blocks.
• Extensive PLC ladder logic used for analog functions, PID, setpoint programmer, alarms, interface with
operator interface, pushbuttons, lamps is replaced by UMC800 function blocks and displays. (Extensive
conditional alarming may expand logic requirements)
• All logic blocks are executed in order according to sequence.
• All fast logic, logic blocks are executed and outputs updated in 100ms - used to capture faster transitions
such as a pushbutton depression on a panel.
• All normal logic blocks are executed at analog update rate.
• You can mix fast and analog scan time logic blocks.
• If you wish Discrete Input function blocks to be scanned prior to execution of succeeding blocks, re-
number their sequence order ahead of these blocks.
• You can place any number of connections to the output of a block, or if using signal tags for this
purpose, they may be used anywhere.
• Internal signal tags used to transfer statuses to other logic circuits do not consume blocks.