User-Programmable Pushbutton Operation - GE D90 Plus Instruction Manual

USER-PROGRAMMABLE PUSHBUTTONS

User-programmable pushbutton operation

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User-programmable pushbuttons provide a simple and error-free way to enter digital state
(on, off) information. The digital state can be entered locally (by directly pressing the front
panel pushbutton) or remotely (via operands) into logic equations, protection elements,
and control elements. Typical applications include breaker control, autorecloser blocking,
setting group changes, and the control of selector switches.
Each pushbutton asserts its own on-state and off-state operands (for example,
and
PUSHBUTTON 1 ON PUSHBUTTON 1
pushbutton and are used to program specific actions. If any pushbutton is active, the
operand asserts.
PB ON
The pushbuttons can be controlled automatically by asserting user-specified operands.
The pushbutton reset status is declared when the
The activation and deactivation of user-programmable pushbuttons depends on whether
latched or self-reset mode is selected.
In latched mode, a pushbutton can be set (activated) by asserting the set operand or by
pressing the pushbutton. The pushbutton maintains the set state until deactivated by the
reset command or after a user-specified time delay. The state of each pushbutton is stored
in non-volatile memory and maintained through a loss of control power. The pushbutton is
reset (deactivated) in latched mode by asserting the reset operand or by pressing the
pushbutton. The pushbutton can also be programmed to reset automatically through
settings. These settings enable the autoreset timer and specify the associated time delay.
The autoreset timer can be used in select-before-operate (SBO) breaker control
applications, where the command type (close/open) or breaker location (feeder number)
must be selected prior to command execution. The selection must reset automatically if
control is not executed within a specified time period.
In self-reset mode, a pushbutton remains active for the time it is pressed (the pulse
duration) plus a user-specified dropout time. If the pushbutton is activated via logic
equations, the pulse duration is specified by only the user-specified dropout time. The time
that the set operand remains assigned has no effect on the pulse duration. The pushbutton
is reset (deactivated) in self-reset mode when a user-specified dropout delay expires.
The pulse duration of the remote set, remote reset, or local pushbutton must be at least
50 ms to operate the pushbutton. This allows the user-programmable pushbuttons to
operate during power cycling events and various system disturbances that can cause
transient assertion of the operating signals.
The local and remote operation of each user-programmable pushbutton can be inhibited
through user settings. If local locking is applied, the pushbutton ignores set and reset
commands executed through the front panel pushbuttons. If remote locking is applied, the
pushbutton ignores set and reset commands executed through logic operands.
The locking functions are not applied to the autorestart feature. In this case, the inhibit
function can be used in SBO control operations to prevent the pushbutton function from
being activated and ensuring one-at-a-time select operation. The locking functions also
can be used to prevent the accidental pressing of the front panel pushbuttons. The
separate inhibit of the local and remote operation simplifies the implementation of local/
remote control supervision.
Pushbutton states can be logged by the sequence of events recorder. In latched mode,
user-defined messages also can be associated with each pushbutton and displayed when
the pushbutton is on or changing to off.
OFF). These operands are available for each
PUSHBUTTON 1 OFF
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 12: LOCAL INTERFACE
ANY
operand is asserted.