Virtual Inputs - GE 845 Instruction Manual

INPUTS

Virtual Inputs

4–128
Figure 4-49: Contact Input Debouncing Mechanism and Time-stamping Sample Timing
The 845 relay is equipped with 32 Virtual Inputs that can be individually programmed to
respond to input signals from the keypad or from communications protocols. This has the
following advantages over Contact Inputs only:
• The number of logic inputs can be increased without introducing additional hardware.
• Logic functions can be invoked from a remote location over a single communication
channel.
• The same logic function can be invoked both locally via contact input or front panel
keypad, and/or remotely via communications.
• Panel switches can be replaced entirely by virtual switches to save cost and wiring.
All Virtual Input operands are defaulted to "Off" (logic 0) unless the appropriate input signal
is received.
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: SETPOINTS