SC Series Controllers
Embedded PLC
Instructions
Description
Use the NEQ instruction to test whether two values are not equal. If source A and source B
are not equal, the instruction is logically true. If the two values are equal, the instruction is
logically false.
NOT
This instruction performs a bit-by-bit logical NOT. The operation is performed using the value
at source A. The result (one's complement of A) is stored in the destination.
NXB
Next Branch
Marks the beginning of another branch.
OR
This instruction performs a bit-by-bit logical OR. The operation is performed using the value
at source A and the value at source B. The result is stored in the destination.
OSR
One Shot Rising
The OSR instruction is a retentive input instruction that triggers an event to occur one time.
Use the OSR instruction when an event must start based on the change of state of the rung
from false-to-true.
When the rung conditions preceding the OSR instruction go from false-to-true, the OSR
instruction will be true for one scan. After one scan is complete, the OSR instruction becomes
false, even if the rung conditions preceding it remain true. The OSR instruction will only
become true again if the rung conditions preceding it transition from false-to-true.
The address assigned to the OSR instruction is not the one-shot address referenced by the
program, nor does it indicate the state of the OSR instruction. This address allows the OSR
instruction to remember its previous rung state.
OTE
Output Energize
Use the OTE instruction in the ladder program to turn on a bit when rung conditions are
evaluated as true.
Output Latch
OTL is a retentive output instruction. OTL can only turn on a bit (while OTU can only turn off
a bit). This instruction is usually used in pair with the OTU instruction. The program can
examine a bit controlled by OTL instructions as often as necessary.
OTL
When rung conditions become false (after being true), the bit remains set and the
corresponding output remains energized.
When enabled, the latch instruction tells the controller to turn on the addressed bit.
Thereafter, the bit remains on, regardless of the rung condition, until the bit is turned off
(typically by an OTU instruction in another rung).
OTU
Output Unlatch
OTU is a retentive output instruction. OTU can only turn off a bit (while OTL can only turn on
a bit). This instruction is usually used in pairs with the OTL instruction. The program can
examine a bit controlled by the OTU instruction as often as necessary.
The unlatch instruction tells the controller to turn off the addressed bit. Thereafter, the bit
remains off, regardless of the rung condition, until it is turned on (typically by an OTL
instruction in another rung).
RES
Reset
Use a RES instruction to reset a timer or counter. When the RES instruction is enabled, it
resets the Timer On Delay (TON), Retentive Timer (RTO), Count Up (CTU) or Count Down
(CTD) instruction having the same address as the RES instruction.
Retentive Timer
Use the RTO instruction to turn an output on or off after its timer has been on for a present
time interval. The RTO instruction is a retentive instruction that begins to count millisecond
intervals when rung conditions become true. The RTO instruction retains its accumulated
value when the rung conditions become false. The Time Base must be 10 msec. The timer
will not work in any other Time Base.
This Bit
RTO
108 / 1032
Is Set When
And Remains Set Until One of
the Following
