Configurable Redundant Output (CROUT)

The Configurable Redundant Output instruction controls and monitors redundant outputs. The reaction time for output feedback is configurable. The instruction supports positive and negative feedback signals.
Available Languages
Ladder Diagram
CROUT_LD_avail_v31
Function Block
This instruction is not available in function block.
Structured Text
This instruction is not available in structured text.
Operands
IMPORTANT:
Unexpected operation, including controller assert or a Major Non-Recoverable Fault, can occur if:
  • Backing tag members are written to.
  • Backing tags are shared by multiple instruction invocations.
  • Backing tag members are passed as parameters to an instruction controlled by the same backing tag.
  • The backing tag
    .EnableIn
     member is referenced anywhere in the program.
    .EnableIn
     is a parameter that represents rung state into an instruction and is only intended for internal use.
    For examples of these incorrect backing tag usages, see Backing tag usages that can cause unexpected operation.
WARNING: If changing instruction operands while in Run mode, accept the pending edits and cycle the controller mode from Program to Run for the changes to take effect.
This table provides the operands used to configure the instruction. These operands cannot be changed at runtime.
Operand
Data type
Format
Description
CROUT
CONFIGURABLE_ROUT
tag
CROUT structure
Feedback Type
BOOL
Drop-down
This operand defines the feedback ON and OFF states.
Positive (1)
ON (1): Feedback 1 ON, Output 1 ON.
OFF (0): Feedback 1 OFF, Output 1 OFF.
Negative (0)
ON (1): Feedback 1 OFF, Output 1 ON.
OFF (0): Feedback 1 ON, Output 1 OFF.
Feedback Reaction Time
DINT
immediate
This operand specifies the amount of time that the instruction waits for Feedback 1 and Feedback 2 to reflect the state of Output 1 and Output 2 as specified by the configured Feedback Type.
The valid range is 5 to 1000 ms.
The following table explains the instruction inputs.
Operand
Data Type
Format
Description
Actuate
BOOL
tag
This input energizes or de-energizes Output 1 and Output 2.
ON (1): Output 1 and Output 2 are energized if no faults exist.
OFF (0): Output 1 and Output 2 are de-energized.
Feedback 1
BOOL
tag
This input is constantly monitored to make sure that it reflects the state of Output 1. When Output 1 transitions, this input must detect the transition within the Feedback Reaction Time.
Feedback 2
BOOL
tag
This input is constantly monitored to make sure that it reflects the state of Output 2. When Output 2 transitions, this input must detect the transition within the Feedback Reaction Time.
Input Status
BOOL
tag
immediate
If instruction inputs are from a safety I/O module, this is the status from the I/O module or modules (Connection Status or Combined Status). If instruction inputs are derived from internal logic, it is the application programmer’s responsibility to determine the conditions.
ON (1): The inputs to this instruction are valid.
OFF (0): The inputs to this instruction are invalid.
Output Status
BOOL
tag
immediate
This input indicates the output status of the I/O module or modules used by this instruction.
ON (1): The I/O connection and the I/O module are operational.
OFF (0): The module has a fault or the connection to the module has been lost.
Reset
1
BOOL
tag
This input clears the instruction faults provided the fault condition is not present.
OFF (0) -> ON (1): The FP and Fault Code outputs are reset.
1
Some safety standards require monitoring the transition of the reset input. When the reset is used to reset a safety function, additional logic may be required to verify a transition of the reset input from High-to-Low or Low-to-High.
The following table explains the instruction outputs.
Operand
Data Type
Description
Output 1 (01)
BOOL
This output is used to control one channel of a two channel output device. Output 1 is de-energized when 1 or more of the following occurs:
  • A feedback fault occurs.
  • Input Status or Output Status inputs become invalid (OFF = 0).
  • The Actuate input turns OFF (0).
Output 2 (02)
BOOL
This output is used to control one channel of a two channel output device. Output 2 is de-energized when 1 or more of the following occurs:
  • A feedback fault occurs.
  • Input Status or Output Status inputs become invalid (OFF = 0).
  • The Actuate input turns OFF (0).
Fault Present (FP)
BOOL
ON (1): A fault is present in the instruction.
OFF (0): The instruction is operating normally.
Fault Code
DINT
This output indicates the type of fault that occurred. See the Fault Codes section below for the list of fault codes.
This parameter is not safety-related.
Diagnostic Code
DINT
This output indicates the diagnostic status of the instruction. See the Diagnostic Codes section below for a list of diagnostic codes.
This parameter is not safety-related.
IMPORTANT: Do not write to any instruction output tag under any circumstances.
Normal Operation
This timing diagram shows normal operation of this instruction to control dual channel outputs when the Feedback Type is Positive. Outputs 1 and 2 are energized at (A) when the Actuate input turns ON (1). Both feedback inputs react before the Feedback Reaction timer has expired, so Output 1 and Output 2 remain energized in steady state at (B). Outputs 1 and 2 are de-energized at (C) when the Actuate input turns OFF (0). At (D), both feedback inputs react before the Feedback Reaction timer has expired, so Output 1 and Output 2 remain de-energized in steady state.
Feedback Fault
A feedback fault can occur when either Feedback 1 or Feedback 2 fails to correctly reflect the state of Output 1 and Output 2. The Feedback Type is configured as Positive in this diagram example. Output 1 and Output 2 are energized at (A), but at (B), Feedback 2 has not turned ON (1) before the Feedback Reaction timer expires, generating a feedback fault. The fault cannot be cleared at (C), because Feedback 1 and Feedback 2 do not yet reflect the state of Output 1 and Output 2. The fault is cleared at (D) when the Reset input turns ON (1) and both Feedback 1 and Feedback 2 are OFF (0), correctly reflecting the state of Output and Output 2.
False Rung State Behavior
When the instruction is executed on a false rung, all instruction outputs are de-energized.
Fault Codes and Corrective Actions
Fault Code
Description
Corrective Action
0
No fault
None
16#20
32
The Input Status input transitioned from ON (1) to OFF (0) while the instruction was executing.
  • Check the I/O module connection.
  • Reset the fault.
16#21
33
The Output Status input transitioned from ON (1) to OFF (0) while the instruction was executing.
  • Check the I/O module connection.
  • Reset the fault.
16#5000
20480
Feedback 1 and Feedback 2 turned OFF (0) unexpectedly.
  • Check the feedback signals.
  • Reset the fault.
16#5001
20481
Feedback 1 turned OFF (0) unexpectedly.
  • Check the feedback 1 signal.
  • Reset the fault.
16#5002
20482
Feedback 2 turned OFF (0) unexpectedly.
  • Check the feedback 2 signal.
  • Reset the fault.
16#5003
20483
Feedback 1 and Feedback 2 turned ON (1) unexpectedly.
  • Check the feedback signal.
  • Reset the fault.
16#5004
20484
Feedback 1 turned ON (1) unexpectedly.
  • Check the feedback 1 signal.
  • Reset the fault.
16#5005
20485
Feedback 2 turned ON (1) unexpectedly.
  • Check the feedback 2 signal.
  • Reset the fault.
16#5006
20486
Feedback 1 and Feedback 2 did not turn ON (1) within the Feedback Reaction Time.
  • Check the feedback signal or adjust the Feedback Reaction Time.
  • Reset the fault.
16#5007
20487
Feedback 1 did not turn ON (1) within the Feedback Reaction Time.
  • Check the feedback 1 signal or adjust the Feedback Reaction Time.
  • Reset the fault.
16#5008
20488
Feedback 2 did not turn ON (1) within the Feedback Reaction Time.
  • Check the feedback 2 signal or adjust the Feedback Reaction Time.
  • Reset the fault.
16#5009
20489
Feedback 1 and Feedback 2 did not turn OFF (0) within the Feedback Reaction Time.
  • Check the feedback signal or adjust the Feedback Reaction Time.
  • Reset the fault.
16#500A
20490
Feedback 1 did not turn OFF (0) within the Feedback Reaction Time.
  • Check the feedback 1 signal or adjust the Feedback Reaction Time.
  • Reset the fault.
16#500B
20491
Feedback 2 did not turn OFF (0) within the Feedback Reaction Time.
  • Check the feedback 2 signal or adjust the Feedback Reaction Time.
  • Reset the fault.
Diagnostic Codes and Corrective Actions
Diagnostic Code
Description
Corrective Action
0
No fault
None
16#20
32
The Input Status was OFF (0) when the instruction started.
Check the I/O module connection.
16#21
33
The Output Status input transitioned from ON (1) to OFF (0) while the instruction was executing.
Check the I/O module connection.
16#5000
20480
The Actuate input is held ON (1).
Set the Actuate input to OFF (0).
Affects Math Status Flags
No
Major/Minor Faults
None specific to this instruction. See Index through arrays for array-indexing faults.
Execution
Condition/State
Action Taken
Prescan
Same as Rung-condition-in is false.
Rung-condition-in is false
The .01 and .02 outputs are cleared to false.
The Diagnostic Code and Fault Code outputs are set to 0
Rung-condition-in is true
The instruction executes.
Postscan
Same as Rung-condition-in is false.
Provide Feedback
Have questions or feedback about this documentation? Please submit your feedback here.
Normal