Basler BE1-CDS220, Instruction Manual

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BE1-CDS220 Protection and Control 4-39
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Time delays less than 10 cycles can be entered to the nearest 0.1 cycles through the HMI. All time
delays can be entered to the nearest 0.01 cycles from the ASCII command interface. Time delays entered
in cycles are converted to milliseconds or seconds. Increment precision after conversion is limited to that
appropriate for each of those units of measure.
Example 1. Make the following operating settings to the 62 element. Figure 4-38 illustrates these
settings.
Time units: ms
T1 Time: 100
T2 Time: 0
Retrieving General Purpose Logic Timers Status from the Relay
The status of each logic variable can be determined from the ASCII command interface by using the RG-
STAT (report general-status) or the RL (report logic) commands. See Section 6,
Reporting and Alarm
Functions, General Status Reporting , for more information.
VIRTUAL SWITCHES
43 - Virtual Selector Switches
The BE1-CDS220 Current Differential System has eight virtual selector switches that can provide manual
control, locally and remotely, without using physical switches and/or interposing relays. Each virtual
switch can be set for one of three modes of operation to emulate virtually any type of binary (two-position)
switch. An example would be an application that requires a ground cutoff switch. The traditional approach
might be to install a switch on the panel and wire the output to a contact sensing input on the relay or in
series with the ground trip output of the relay. Instead, a virtual switch can be used to reduce costs with
the added benefit of being able to operate the switch both locally through the HMI and remotely from a
substation computer or through a modem connection to a remote operator's console.
The state of the switches can be controlled from the optional HMI or ASCII command interface. Control
actions can be set by the BESTlogic mode setting. When set for
On/Off/Pulse , each switch can be
controlled to open (logic 0), close (logic 1), or pulse such that the output toggles from its current state to
the opposite state and then returns. Additional modes allow the switch operation to be restricted. In
On/Off , the switch emulates a two-position selector switch, and only open and close commands are
accepted. In Off/Momentary On , a momentary close, spring-return switch is emulated and only the pulse
command is accepted. Because switch status information is saved in nonvolatile memory, the relay
powers up with the switches in the same state as when the relay was powered down.
Each virtual selector switch element (see Figure 4-39) has one output: 43, 143, 243, 343, 443, 543, 643,
and 743 . The output is TRUE when the switch is in the closed state; the output is FALSE when the switch
is the open state. Since both the output and the inverse of the output of these switches can be used as
many times as desired in your programmable logic, they can emulate a switch with as many normally
open and normally closed decks as desired.
Figure 4-39. Virtual Selector Switches Logic Block
User specified labels could be assigned to each virtual switch and to both states of each switch. In the
previous ground cutoff switch example, you might enable one of the switches in BESTlogic as Mode 2,
ON/OFF and connect the output of that switch to the blocking input of the 87 protection element. This
would disable the differential protection when the switch is closed (logic 1) and enable it when the switch