7.6
SEL-351A Relay Instruction Manual Date Code 20080213
Inputs, Outputs, Timers, and Other Control Logic
Local Control Switches (Only on Models With LCD)
Figure 7.4 Local Control Switch Configured as an ON/OFF Switch
OFF/MOMENTARY Switch
The local bit LBn is maintained in the OFF (LBn = logical 0) position and
pulses to the MOMENTARY (LBn = logical 1) position for one processing
interval (1/4 cycle).
Figure 7.5 Local Control Switch Configured as an OFF/MOMENTARY Switch
ON/OFF/MOMENTARY Switch
The local bit LBn:
is in either the ON (LBn = logical 1) or OFF (LBn = logical 0) position
or
is in the OFF (LBn = logical 0) position and pulses to the MOMENTARY
(LBn = logical 1) position for one processing interval (1/4 cycle).
Figure 7.6 Local Control Switch Configured as an ON/OFF/MOMENTARY
Switch
Disable local control switches by “nulling out” all the label settings for that
switch (see Section 9: Setting the Relay). The local bit associated with this
disabled local control switch is then fixed at logical 0.
Logical 1
LBn
(n = 1 through 16)
ON Position
OFF Position
(Logical 0)
Relay
Word
Bit
Logical 1
LBn
(n = 1 through 16)
OFF Position
(Logical 0)
MOMENTARY Position
Relay
Word
Bit
Table 7.2 Correspondence Between Local Control Switch Types and
Required Label Settings
Local Switch Type Label NLBn Label CLBn Label SLBn Label PLBn
ON/OFF X X X
OFF/MOMENTARY X X X
ON/OFF/MOMENTARY X X X X
Logical 1
LBn
(n = 1 through 16)
ON Position
OFF Position
(Logical 0)
MOMENTARY Position
Relay
Word
Bit
Courtesy of NationalSwitchgear.com
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