OSF (One Shot Falling) Ladder Logic Instruction

Definition

Ladder logic output instruction that writes bit data to a referenced Storage Bit and an Output Bit. The Output Bit is set or cleared depending on the Storage Bit. The instruction sets the Storage Bit if the preceding logic is true and clears it when false. The Output Bit is set for one program scan when the Storage bit is cleared.  The Storage Bit is cleared when the preceding logic is false. This instruction provides a one shot output bit, triggered when the preceding logic transitions from true to false. The OSR (One Shot Rising) bit provides the one shot output bit when the preceding logic is true.

List of arguments

BOOL TAG           Storage Bit

BOOL TAG           Output Bit

Important Note: Do not reference a Boolean tag to more than one OSF instruction.

OSR (One Shot Rising) Ladder Logic Instruction

Definition

Ladder logic output instruction that writes bit data to a referenced Storage Bit and an Output Bit. The Output Bit is set or cleared depending on the Storage Bit. The instruction sets the Storage Bit if the preceding logic is true and clears it when false. The Output Bit is set for one program scan when the Storage bit is set.  The Storage Bit is cleared when the preceding logic is false. This instruction provides a one shot output bit, triggered when the preceding logic transitions from false to true. The OSF (One Shot Falling) bit provides the one shot output bit when the preceding logic is false.

List of arguments

BOOL TAG           Storage Bit

BOOL TAG           Output Bit

Important Note: Do not reference a Boolean tag to more than one OSR instruction.

ONS (One Shot) Ladder Logic Instruction

Definition

Ladder logic output instruction that writes bit data referenced by an associated tag. The instruction sets the referenced bit if the preceding logic is true and clears it if false. Logic to the right of the One Shot will execute for one program scan.

List of arguments

BOOL TAG

Important Note: Do not reference a Boolean tag to more than one ONS instruction.

OTL and OTU (Output Latch & Output Unlatch) Ladder Logic Instructions

Definition

Ladder logic output instructions which write bit data referenced by an associated tag. The OTL instruction sets the referenced bit while the OTU instruction clears the bit. These instructions are used in pairs, meaning both instructions will reference the same tag.

List of arguments

BOOL TAG

Important Note: The data referenced by the tag is not cleared upon prescan or postscan.  In other words the data is retentive. Powering down the processor or putting it in program mode will not clear a bit that has been latched on.

OTE (Output Energize) Ladder Logic Instruction

Definition

Ladder logic output instruction that writes bit data referenced by an associated tag. The instruction sets the referenced bit to 1 if the preceding logic is true and 0 if false.

List of arguments

BOOL TAG

XIO (Examine If Open) Ladder Logic Instruction

Definition

Ladder logic input instruction that evaluates bit data referenced by an associated tag. The instruction output is true if the value is 0 and false if the value is 1.

List of arguments:

BOOL TAG

XIC (Examine If Closed) Ladder Logic Instruction

Definition

Ladder logic input instruction that evaluates bit data referenced by an associated tag. The instruction output is true if the value is 1 and false if the value is 0.

List of arguments:

BOOL TAG

 

Bit Instructions

The XIC and XIO instructions are input instructions.

Input instructions do not alter data. The instructions simply check the data referenced by the associated tag and executes logic based on the data.

In the case of the XIC instruction

when the tags value is 1 the instruction is true enabling instructions to the right to execute. If the tags value is 0 the instruction is false disabling instructions to the right.

In the case of the XIO instruction

when the tags value is 0 the instruction is true enabling instructions to the right to execute. If the tags value is 1 the instruction is false disabling instructions to the right. Read More