Programmable Safety Controller SCR P
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6.6.2 Virtual ON/OFF and Mute Enable
Virtual ON/OFF
Provides an ON or OFF command to the machine. When all of the controlling safety inputs are in the Run state, this
function permits the safety output to turn ON and OFF. The Run state is a logical 1 and the Stop state is a logical 0.
A virtual ON/OFF input can be added without mapping to a safety output, allowing it to control a non-safety status
output. An ON/OFF switch can also be created using a physical input; see
Virtual Mute Enable
Signals the Safety Controller when the mute sensors are permitted to perform a mute function. When the mute
enable function is configured, the mute sensors are not enabled to perform a mute function until the mute enable
signal is in the Run state. The enable (Run) state is a logical 1 and the disable (Stop) state is a logical 0. A mute
enable switch can also be created using a physical input; see
6.7 Safety Outputs
SCR P
The SCR P-2 has two isolated redundant relay outputs. Each relay output has 3 independent sets of contacts. See
on p. 12 for rating and derating considerations.
The following list describes additional nodes and attributes that can be configured from the Safety Output function block
Properties
window (see
Adding Inputs and Status Outputs
EDM (External Device Monitoring)
Enables the Safety Controller to monitor devices under control (FSDs and MPCEs) for proper response to the
stopping command of the safety outputs.
It is strongly recommended to incorporate EDM (or AVM)
in the
machine design and the Safety Controller configuration to ensure the proper level of safety circuit integrity (see
EDM and FSD Hookup
AVM (Adjustable Valve Monitoring)
Enables the Safety Controller to monitor valves or other devices that may become slow, stick, or fail in an energized
state or position and whose operation needs to be verified after a Stop signal occurs. Up to three AVM inputs can be
selected if EDM is not used
. It is strongly recommended to incorporate AVM (or EDM)
in the machine design
and the Safety Controller configuration to ensure the proper level of safety circuit integrity (see
on p. 33).
LR (Latch Reset)
Keeps the SO or RO output Off until the input changes to the Run state and a manual reset operation is performed
See
on p. 36 for more information.
RE (Reset Enable)
This option appears only if
LR (Latch Reset)
is enabled. The
Latch Reset
can be controlled by selecting
Reset Enable
to restrict when the Safety Output can be reset to a Run condition.
FR (Fault Reset)
Provides a manual reset function when input faults occur. The FR node needs to be connected to a Manual Reset
button or signal. This function is used to keep the SO or RO output Off until the Input device fault is cleared, the
faulted device is in the Run state, and a manual reset operation is performed. This replaces power down/up cycle
reset operation. See
on p. 36 for more information.
Power up mode
The Safety Output can be configured for three power-up scenarios (operational characteristics when power is
applied):
• Normal Power-Up Mode (default)
• Manual Power-up Mode
• Automatic Power-Up Mode
See
on p. 36 for more information.
WARNING:
Safety Outputs must be connected to the machine control so that the machine’s safety-
related control system interrupts the circuit to the machine primary control element(s), resulting in a non-
hazardous condition.
Do not wire an intermediate device(s), such as a PLC, PES, or PC, that can fail in such a manner that
there is the loss of the safety stop command, or that the safety function can be suspended, overridden,
or defeated, unless accomplished with the same or greater degree of safety.
