Input and Output Line Conditioning
Safety I/O modules provide pulse test and monitoring capabilities. If the module detects a failure, it sets the offending input or output to the Safe state and reports the failure to the controller.
The failure indication is made via the input or output point status, and is maintained for a configurable amount of time, or until the failure is repaired, which ever comes last.
IMPORTANT:
Ladder logic must be included in the application program to latch these I/O point failures and ensure proper restart behavior.
For more information on Safety I/O modules, refer to the publications listed in Additional resources.
I/O Module Connection Status
A CIP Safety
TM
system provides connection status for each I/O device in the safety system. If an input connection failure is detected, the operating system sets all associated inputs to the de-energized (Safe) state, and reports the failure to the ladder logic. If an output connection failure is detected, the operating system can only report the failure to the ladder logic.
IMPORTANT:
Ladder logic must be included in the application program to latch these I/O point failures and ensure proper restart behavior.
How to Latch and Reset Faulted I/O
The following diagrams provide examples of the ladder logic required to latch and reset an I/O module connection or point failure. The first image shows the ladder logic for an input point, and the second shows the ladder logic for an output point.
IMPORTANT:
Both of these diagrams are examples, and are for illustrative purposes only. The suitability of this logic depends upon your specific system requirements.
TIP:
The safety instructions shown throughout this manual can manage the fault and reset conditions of safety inputs and outputs. If you do not use safety instructions, additional programming may be required to manage fault latching and recovery.
Input latch logic:
The first rung monitors a Reset input and provides a reset on the falling edge of the Reset_PB (ResetOB).
The second rung latches an internal indication that either the module connection or the specific input point has failed. The latched fault resets on the falling edge of the Reset_PB only if the fault has been repaired. This prevents the safety function from automatically restarting if the Fault Reset signal gets stuck on.
The third rung shows the input point data used in combination with the internal fault indication to control an output.
The output is internal data that may be used in combinational logic later to drive an actual output. If an actual output is used directly, it may or may not require logic similar to that shown in Figure 1.3 for latching and resetting output connection failures.
The Fault Reset contact shown in these examples is typically activated as a result of operator action. The Fault Reset could be derived as a result of combinational logic or directly from an input point (in which case it may or may not require conditioning of its own).
Output latch logic:
The ladder logic in the output example has a similar latch and reset concept as that shown in the input example.
The first rung monitors a Reset input and provides a reset on the falling edge of the Reset_PB (ResetOB).
The second rung latches an internal indication that either the module connection or the specific output point has failed. The latched fault resets on the falling edge of the Reset_PB only if the fault has been repaired. This prevents the safety function from automatically restarting if the Fault Reset signal gets stuck on.
The third rung includes application-specific logic to drive the state of an output point. This logic is conditioned by the output faulted internal indicator.
False Rung State Behavior
The information provided in this manual regarding the
GuardLogix
Safety application instructions depicts the "True Rung State" (Ladder Diagram Logic) behavior of the instructions.The "False Rung State" behavior is exactly the same (internal state machines continue to run and change states based on the inputs) except that all outputs, including prompts and fault indicators, are set to zero when the instructions are disabled or on a false rung.
I/O Point Mapping
Input
These tables identify the mapping between the Safety I/O module’s Input points and the controller tags when the Safety I/O module’s Input Status module definition is configured for Point Status or Combined Status.
moduleName
is the name you assign to the I/O module. Slot
is the chassis slot that the module occupies.Mapping for 1732 and 1791 Safety I/O modules:
I/O Module Point | Controller Tag Reference | ||
Data | Point Status | Combined Status | |
IN 0 | moduleName :I.Pt00Data | moduleName :I.Pt00InputStatus | moduleName :I.CombinedInputStatus |
IN 1 | moduleName :I.Pt01Data | moduleName :I.Pt01InputStatus | |
IN 2 | moduleName :I.Pt02Data | moduleName :I.Pt02InputStatus | |
… | … | … | |
IN n | moduleName :I.PtnData | moduleName :I.PtnInputStatus | |
Mapping for 1734 Safety I/O modules:
I/O Module Point | Controller Tag Reference | ||
Data | Point Status | Combined Status | |
IN 0 | AdapterName :slot :I.Pt00Data | AdapterName :slot :I.Pt00Status | AdapterName :slot :I.CombinedInputStatus |
IN 1 | AdapterName :slot :I.Pt01Data | AdapterName :slot :I.Pt01Status | |
IN 2 | AdapterName :slot :I.Pt02Data | AdapterName :slot :I.Pt02Status | |
… | … | … | |
IN n | AdapterName :slot :I.PtnData | AdapterName :slot :I.PtnStatus | |
Mapping for 1756, 5069, and 5094 Safety I/O modules:
I/O Module Point | Controller Tag Reference | ||
Data | Point Status | Combined Status | |
IN 0 | AdapterName :slot :I.Pt00.Data | AdapterName :slot :I.Pt00.Status | Not applicable |
IN 1 | AdapterName :slot :I.Pt01.Data | AdapterName :slot :I.Pt01.Status | |
IN 2 | AdapterName :slot :I.Pt02.Data | AdapterName :slot :I.Pt02.Status | |
… | … | … | |
IN n | AdapterName :slot :I.Ptn.Data | AdapterName :slot :I.Ptn.Status | |
TIP:
For 1756 and 5069 modules in chassis I/O applications,
Local
replaces AdapterName
.Output
These tables identify the mapping between the Safety I/O module’s Output points and the controller tags when the Safety I/O module’s Input Status module definition is configured for Point Status or Combined Status.
ModuleName
is the name you assign to the I/O module. Slot
is the chassis slot that the module occupies.Mapping for 1732 and 1791 Safety I/O modules:
I/O Module Point | Controller Tag Reference | ||
Data | Point Status | Combined Status | |
OUT 0 | moduleName :O.Pt00Data | moduleName :I.Pt00OutputStatus | moduleName :I.CombinedOutputStatus |
OUT 1 | moduleName :O.Pt01Data | moduleName :I.Pt01OutputStatus | |
OUT 2 | moduleName :O.Pt02Data | moduleName :I.Pt02OutputStatus | |
… | … | … | |
OUT n | moduleName :O.PtnData | moduleName :I.PtnOutputStatus | |
Mapping for 1734 Safety I/O modules:
I/O Module Point | Controller Tag Reference | ||
Data | Point Status | Combined Status | |
OUT 0 | AdapterName :slot :O.Pt00Data | AdapterName :slot :I.Pt00OutputStatus | moduleName :I.CombinedOutputStatus |
OUT 1 | AdapterName :slot :O.Pt01Data | AdapterName :slot :I.Pt01OutputStatus | |
OUT 2 | AdapterName :slot :O.Pt02Data | AdapterName :slot :I.Pt02OutputStatus | |
… | … | … | |
OUT n | AdapterName :slot :O.PtnData | AdapterName :slot :I.PtnOutputStatus | |
Mapping for 1756, 5069, and 5094 Safety I/O modules:
I/O Module Point | Controller Tag Reference | ||
Data | Point Status | Combined Status | |
OUT 0 | AdapterName :slot :O.Pt00.Data | AdapterName :slot :I.Pt00.Status | Not applicable |
OUT 1 | AdapterName :slot :O.Pt01.Data | AdapterName :slot :I.Pt01.Status | |
OUT 2 | AdapterName :slot :O.Pt02.Data | AdapterName :slot :I.Pt02.Status | |
… | … | … | |
OUT n | AdapterName :slot :O.Ptn.Data | AdapterName :slot :I.Ptn.Status | |
TIP:
For 1756 and 5069 modules in chassis I/O applications,
Local
replaces AdapterName
.Provide Feedback