7.9
Date Code 20080213 Instruction Manual SEL-351A Relay
Inputs, Outputs, Timers, and Other Control Logic
Remote Control Switches
Remote Control Switches
Remote control switches are operated via the serial communications port only
(see CON Command (Control Remote Bit) on page 10.36).
Figure 7.9 Remote Control Switches Drive Remote Bits RB1āRB16
The outputs of the remote control switches in Figure 7.9 are Relay Word bits
RBn (n = 1 to 16), called remote bits. Use these remote bits in SEL
OGIC
control equations.
Any given remote control switch can be put in one of the following three
positions:
Remote Bit
Application Ideas
With SELOGIC control equations, the remote bits can be used in applications
similar to those that local bits are used in (see preceding local control switch
discussion).
Also, remote bits can be used much as optoisolated inputs are used in
operating latch control switches (see discussion following Figure 7.14). Pulse
(momentarily operate) the remote bits for this application.
Remote Bit States
Not Retained When
Power Is Lost
The states of the remote bits (Relay Word bits RB1āRB16) are not retained if
power to the relay is lost and then restored. The remote control switches
always come back in the OFF position (corresponding remote bit is deasserted
to logical 0) when power is restored to the relay.
Remote Bit States
Retained When
Settings Changed or
Active Setting Group
Changed
The state of each remote bit (Relay Word bits RB1āRB16) is retained if relay
settings are changed (for the active setting group or one of the other setting
groups) or the active setting group is changed. If a remote control switch is in
the ON position (corresponding remote bit is asserted to logical 1) before a
setting change or an active setting group change, it comes back in the ON
position (corresponding remote bit is still asserted to logical 1) after the
change. If a remote control switch is in the OFF position (corresponding
remote bit is deasserted to logical 0) before a settings change or an active
setting group change, it comes back in the OFF position (corresponding
remote bit is still deasserted to logical 0) after the change.
If settings are changed for a setting group other than the active setting group,
there is no interruption of the remote bits (the relay is not momentarily
disabled).
ON (logical 1)
OFF (logical 0)
MOMENTARY (logical 1 for one processing interval)
Logical 1
RBn
(n = 1 through 16)
ON Position
(Maintained Logical 1 Position)
OFF Position
(Maintained Logical 0 Position)
MOMENTARY Position
(Logical 1 for One Processing Interval)
Relay
Word
Bit
Courtesy of NationalSwitchgear.com