GE C70, Instruction Manual

Page: 335 / 708

GE Multilin C70 Capacitor Bank Protection and Control System 5-211
5 SETTINGS 5.7 CONTROL ELEMENTS
5
The selector switch element is intended to replace a mechanical selector switch. Typical applications include setting group
control or control of multiple logic sub-circuits in user-programmable logic.
The element provides for two control inputs. The step-up control allows stepping through selector position one step at a
time with each pulse of the control input, such as a user-programmable pushbutton. The three-bit control input allows set-
ting the selector to the position defined by a three-bit word.
The element allows pre-selecting a new position without applying it. The pre-selected position gets applied either after time-
out or upon acknowledgement via separate inputs (user setting). The selector position is stored in non-volatile memory.
Upon power-up, either the previous position is restored or the relay synchronizes to the current three-bit word (user set-
ting). Basic alarm functionality alerts the user under abnormal conditions; for example, the three-bit control input being out
of range.
A selector switch runs every two power cycles.
• SELECTOR 1 FULL RANGE : This setting defines the upper position of the selector. When stepping up through avail-
able positions of the selector, the upper position wraps up to the lower position (position 1). When using a direct three-
bit control word for programming the selector to a desired position, the change would take place only if the control word
is within the range of 1 to the
SELECTOR FULL RANGE
. If the control word is outside the range, an alarm is established
by setting the
SELECTOR ALARM
FlexLogic operand for 3 seconds.
• SELECTOR 1 TIME-OUT: This setting defines the time-out period for the selector. This value is used by the relay in
the following two ways. When the
SELECTOR STEP-UP MODE
is “Time-out”, the setting specifies the required period of
inactivity of the control input after which the pre-selected position is automatically applied. When the
SELECTOR STEP-
UP MODE
is “Acknowledge”, the setting specifies the period of time for the acknowledging input to appear. The timer is
re-started by any activity of the control input. The acknowledging input must come before the
SELECTOR 1 TIME-OUT
timer expires; otherwise, the change will not take place and an alarm will be set.
• SELECTOR 1 STEP-UP : This setting specifies a control input for the selector switch. The switch is shifted to a new
position at each rising edge of this signal. The position changes incrementally, wrapping up from the last (
SELECTOR 1
FULL RANGE
) to the first (position 1). Consecutive pulses of this control operand must not occur faster than every
50 ms. After each rising edge of the assigned operand, the time-out timer is restarted and the
SELECTOR SWITCH 1:
POS Z CHNG INITIATED
target message is displayed, where Z the pre-selected position. The message is displayed for
the time specified by the
FLASH MESSAGE TIME
setting. The pre-selected position is applied after the selector times out
(“Time-out” mode), or when the acknowledging signal appears before the element times out (“Acknowledge” mode).
When the new position is applied, the relay displays the
SELECTOR SWITCH 1: POSITION Z IN USE
message. Typically,
a user-programmable pushbutton is configured as the stepping up control input.
• SELECTOR 1 STEP-UP MODE : This setting defines the selector mode of operation. When set to “Time-out”, the
selector will change its position after a pre-defined period of inactivity at the control input. The change is automatic and
does not require any explicit confirmation of the intent to change the selector's position. When set to “Acknowledge”,
the selector will change its position only after the intent is confirmed through a separate acknowledging signal. If the
acknowledging signal does not appear within a pre-defined period of time, the selector does not accept the change
and an alarm is established by setting the
SELECTOR STP ALARM
output FlexLogic operand for 3 seconds.
• SELECTOR 1 ACK : This setting specifies an acknowledging input for the stepping up control input. The pre-selected
position is applied on the rising edge of the assigned operand. This setting is active only under “Acknowledge” mode of
operation. The acknowledging signal must appear within the time defined by the
SELECTOR 1 TIME-OUT
setting after the
last activity of the control input. A user-programmable pushbutton is typically configured as the acknowledging input.
• SELECTOR 1 3BIT A0, A1, and A2 : These settings specify a three-bit control input of the selector. The three-bit con-
trol word pre-selects the position using the following encoding convention:
A2 A1 A0 POSITION
0 0 0 rest
0 0 1 1
0 1 0 2
0 1 1 3
1 0 0 4
1 0 1 5
1 1 0 6
1 1 1 7