Instruction Set

PLCLogix 500 features 65 instructions and PLCLogix 5000 has 80 instructions. These instructions encompass all of the main programming commands associated with either the Logix 500 or 5000 PLC. The PLCLogix Instruction Set consists of the following groups of commands: Bit Instructions, Timer and Counter Instructions, Program Control, Compare, Math, Advanced Math, Move/Logical, Array Shift and Sequencer Instructions.

Select the instruction set by choosing either PLCLogix 500 or 5000 in the Instruction Set Groups shown below:

Instruction Set Groups

PLCLogix 500   PLCLogix 5000

Bit Instructions
Mnemonic Name Symbol Description
XIC Examine If Closed Examines a bit for an On (set, high) condition.
XIO Examine If Open Examines a bit for an Off (cleared, low) condition.
OTE Output Energize When rung conditions are true, the OTE will either set or clear the data bit.
OTL Output Latch When enabled, the instruction signals to the controller to turn on the addressed bit. The bit remains on, regardless of the rung condition.
OTU Output Unlatch When enabled, it clears (unlatches) the data bit. The bit remains Off, regardless of rung condition.
ONS One Shot Enable/disable outputs for one scan when rung is true. The status of the storage bit determines whether this instruction enables or disables the rest of the rung.
OSR One Shot Rising This instruction is a retentive input instruction that triggers an event to occur once. It either sets or clears the output bit, depending on the storage bit status
OSR One Shot Rising This instruction is a retentive input instruction that triggers an event to occur once. It either sets or clears the output bit, depending on the storage bit status
OSF One Shot Falling This instruction either sets or clears the output bit, depending on the storage bit’s status.
Timer and Counter Instructions
Mnemonic Name Symbol Description
TON Timer On Delay A non-retentive timer that accumulates time when the instruction is enabled. The accumulated value is reset when rung conditions go false.
TOF Timer Off Delay A non-retentive timer that accumulates time when the rung makes a true-to-false transition.
RTO Retentive Timer On A retentive timer that accumulates time when the instruction is enabled. Retains its accumulated value when rung conditions become false.
TON Count Up An instruction that counts false-to-true rung transitions. It counts upward and the accumulated value is incremented by one count on each of these transitions.
TOF Count Down This instruction counts downward on each false-to-true rung transition. The accumulated value is decremented by one count on each of these transitions.
RTO Retentive Timer On A retentive timer that accumulates time when the instruction is enabled. Retains its accumulated value when rung conditions become false.
CTU Count Up An instruction that counts false-to-true rung transitions. It counts upward and the accumulated value is incremented by one count on each of these transitions.
CTD Count Down This instruction counts downward on each false-to-true rung transition. The accumulated value is decremented by one count on each of these transitions.
RES Reset This instruction is used to reset a timer, counter or control structure. The accumulated value of these instructions are cleared when the RES instruction is enabled.
Program Control Instructions
Mnemonic Name Symbol Description
JSR Jump to Subroutine
This instruction jumps execution to a specific routine and initiates the execution of this routine, called a subroutine.
SBR Subroutine Stores recurring sections of program logic.
RET Return Used to return to the instruction following the a JSR operation.
JMP Jump to Label Skips sections of ladder logic.
LBL Label Target of the JMP instruction with the same label name.
MCR Master Cont. Res.
Used in pairs to create a program zone that can disable all rungs between the MCR instructions.
AFI Always False Disables all instructions on a rung.
NOP No Operation This instruction functions as a placeholder.
TND Temporary End When enabled, it lets the controller execute logic only up to this instruction.
IOT Immediate Output This instruction immediately updates the specified output data.
Compare Instructions
Mnemonic Name Symbol Description
EQU Equal This instruction is used to test whether two values are equal. If Source A is equal to Source B, the instruction is logically true.
GEQ Greater Than or Equal To Determines whether Source A is greater than or equal to Source B. If the value at Source A is greater than or equal to the value at Source B, then the instruction is true.
GRT Greater Than This instruction is used to test whether one value (Source A) is greater than another value (Source B).
LEQ Less Than or Equal To Determines whether one value (Source A) is less than or equal to another (Source B).
LES Less Than
This instruction determines whether Source A is less than Source B.
LIM Limit This instruction is used to test for values within the range of the Low Limit to the High Limit.
MEQ Mask Equal To Passes the Source and Compare values through a Mask and compares the results.
NEQ Not Equal To This instruction tests whether Source A is not equal to Source B.
Math Instructions
Mnemonic Name Symbol Description
ADD Add Adds Source A to Source B and stores the result in the Destination.
SUB Subtract Subtracts Source B from Source A and places the result in the Destination.
MUL Multiply Multiplies Source A by Source B and stores the result in the destination.
DIV Divide Divides Source A by Source B and places the result in the Destination.
MOD Modulo Divides Source A by Source B and stores the remainder in the Destination.
SQR Square Root Calculates the square root of the source and places the integer result in the Destination.
NEG Negate Changes the sign (+, -) of the Source and stores the result in the Destination.
ABS Absolute Takes the absolute value of the Source and places the result in the Destination.
Math Conversions
Mnemonic Name Symbol Description
TOD Convert to BCD This instruction converts a decimal value to a BCD value and stores the result in the Destination.
FRD Convert to Integer Converts a BCD value (Source) to a decimal value and stores the result in the Destination.
DEG Degrees Converts the Source (in radians) to degrees and places the result in the Destination.
RAD Radians
Converts the Source (in degrees) to radians and stores the result in the Destination.
TRN Truncate Removes the fractional part of the Source and places the result in the Destination.
Advanced Math Instructions
Mnemonic Name Symbol Description
SIN Sine Takes the sine of the Source value (in radians} and places the result in the Destination.
COS Cosine Takes the cosine of the Source value (in radians) and places the result in the Destination.
TAN Tangent Takes the tangent of the Source value (in radians) and stores the result in the Destination.
ASN Arc Sine Takes the arc sine of the Source value and places the result in the Destination (in radians).
ACS Arc Cosine Takes the arc cosine of the Source value and stores the result in the Destination (in radians).
ATN Arc Tangent Takes the arc tangent of the Source value and stores the result in the Destination (in radians).
LN Natural Log Takes the natural log of the Source value and stores the result in the Destination.
LOG Log to the Base 10 Takes the log base 10 of the Source value and stores the result in the Destination.
XPY X to the power Y Takes Source A (X) to the power of Source B (Y) and stores the result in the Destination.
Move/Logical Instructions
Mnemonic Name Symbol Description
MOV Move Copies the Source (which remains unchanged) to the Destination.
MVM Masked Move
Copies the Source to a Destination and allows segments of the data to be masked.
CLR Clear
Clears all the bits of the Destination.
DTR Data Transitional Passes the Source value through a Mask and compares the result with the Reference value.
SWPB Swap Byte Instruction Rearranges the bytes of a tag and stores the bytes in the new order.
SWP Swap Byte Instruction Swaps the lower and higher bytes of a specified number of words.
BTD Bit Field Distribute Copies the specified bits from the Source, shifts the bits to the appropriate position, and writes the bits into the Destination.
AND Bitwise AND Performs a logical AND operation by using the bits in Source A and Source B and placing the result in the Destination.
OR Bitwise OR Performs a logical AND operation by using the bits in Source A and Source B and placing the result in the Destination.
XOR Bitwise Exclusive OR Performs a bitwise XOR operation using the bits in Source A and Source B and stores the result in the Destination.
NOT Bitwise NOT Executes a bitwise NOT operation by using the bits in the Source and placing the result in the Destination
Array Shift Instructions
Mnemonic Name Symbol Description
BSL Bit Shift Left Shifts the specified bits within the Array one position left.
BSR Bit Shift Right
Shifts the specified bits within the Array one position right.
COP Copy File Copies the value in the Source to the Destination.
FLL File Fill Fills elements of an array with the Source value, while the Source remains unchanged.
AVE File Average Calculates the average of a set of values.
FFL FIFO Load Copies the Source Value into a FIFO stack on successive false-to-true transitions.
FFU FIFO Unload Unloads the Source value from the first position of the FIFO and stores that value in the Destination.
LFL LIFO Load
Copies the Source value to the LIFO.
LFU LIFO Unload Unloads the value at .POS of the LIFO and stores 0 in that location.
SRT File Sort Sorts a set of values in one dimension of the Array into ascending order.
STD File Standard Deviation Calculates the standard deviation of a set of values in one dimension of the Array and stores the result in the Destination.
SIZ Size in Elements Determines the size of a dimension of an array and stores the number of elements in the specified dimension of the array
SIZE Size in Elements Determines the size of a dimension of an array and stores the number of elements in the specified dimension of the array
Sequencer Instructions
Mnemonic Name Symbol Description
SQI Sequencer Input Detects when a step is complete in a sequence pair of SQO/SQI instructions.
SQO Sequencer Output Sets output conditions for the next step of sequence pair of SQO/SQI or SQO/SQC instructions.
SQL Sequencer Load Loads reference conditions into a sequencer array.
SQC Sequencer Compare
Detects when a step is complete in a sequence pair of SQO/SQC instructions. RSLogix 500 instruction, supported by PLCLogix.
« Previous  |  Next »