The Modulo instruction is a ladder logic rung output instruction that divides two values and retains the remainder. The instruction is enabled when the preceding logic is true and disabled otherwise.  Source A is divided by Source B and the remainder is placed in the Destination tag. The values can be constants, tags or any combination. A minor … Read more

The Mask Equal To instruction is a ladder logic rung input instruction that compares a source value to a compare value through a mask. If the adjusted source and compare values are equal the logic to the right of the instruction, or rung-condition-out, is enabled and disabled if otherwise. The Source value, Mask value and Compare value can be constants, … Read more

The MCR instruction is used as a soft emergency stop. Rungs placed between two MCR instructions can be disabled; or rather the outputs of the rungs are disabled when the MCR instruction is false and enabled when true. There are a couple of rules to follow:             Don’t jump into an MCR zone as unexpected … Read more

The Natural Log instruction is a ladder logic rung output instruction that takes the log base 10 of the Source value and places the result in the Destination tag. The instruction is enabled when the preceding logic is true and disabled otherwise. The values can be constants, tags or any combination The Source value should … Read more

The Natural Log instruction is a ladder logic rung output instruction that takes the natural log of the Source value and places the result in the Destination tag. The instruction is enabled when the preceding logic is true and disabled otherwise. The values can be constants, tags or any combination. The Source value should be … Read more

The Limit instruction is a ladder logic rung input instruction that compares a test value against a high and low limit. If the test value is in range logic to the right of the instruction, or rung-condition-out, is enabled and disabled if the test value is out of range. The high limit, low limit and … Read more

The Less Than instruction is a ladder logic rung input instruction that compares two values. If Source A is less than Source B the logic to the right of the instruction, or rung-condition-out, is enabled and disabled otherwise. The values can be constants, tags or any combination. Strings can be compared. The software compares the … Read more

The Less Than or Equal To instruction is a ladder logic rung input instruction that compares two values. If Source A is less than or equal to Source B the logic to the right of the instruction, or rung-condition-out, is enabled and disabled otherwise. The values can be constants, tags or any combination. Strings can … Read more

The Label instruction is used in conjunction with a Jump instruction. When the JMP instruction is enabled, the code between the JMP and LBL instruction is not executed. Code execution begins immediately after the LBL instruction. When the JMP instruction is disabled the code between the JMP and LBL instruction is executed normally. A LBL … Read more

JSR Definition The JSR instruction is a ladder logic rung output instruction.  When the instruction is scanned program execution jumps to the subroutine named in the JSR instruction. After the called subroutine is executed the logic execution continues from the rung the subroutine was called from. The instruction is enabled when the preceding logic is … Read more