Safety relays and control modules differ from conventional relays in that they have force-guided (positive-driven) contacts. Three relays are used in a safety relay module. One relay checks the condition of the other two and signals a failure. In addition, safety relays and control modules may be configured as either a single channel or dual channel. Single channel safety relays are capable of accepting only one normally closed (NC) input. When used in safety circuits, they are unable to detect a short circuit failure or a failure of the monitored input to change state. Dual channel safety relays ensure safety system integrity even if one logic circuit fails. |
Products & Services Related to Safety Relays and Control Modules
Emergency Stop Switches
Emergency stop switches are devices that users manipulate to initiate the complete shutdown of a machine, system, or process.
Intrinsic Safety Barriers
Intrinsic safety (IS) barriers are devices that limit the current, voltage, and total energy delivered to a sensor in a hazardous area or flammable environment in order to prevent an explosion.
Light Curtains
Light curtains are photoelectric transmitters that project an array of synchronized,parallel infrared light beams to a receiver unit. When an opaque object interrupts one or more beams, the light curtain controller sends a stop signal to the guarded machine. Light curtains are used as personal safety devices around hazardous machinery or for permiter guarding.
Mechanical Safety Interlock Switches
Mechanical safety interlock switches couple a moveable guard door with the power source of the hazard. When the guard door is opened, the power is isolated, ensuring that the machine does not pose a hazard while an operator requires access.
Noncontact Safety Interlock Switches
Noncontact safety interlock switches couple a moveable guard door with the power source of the hazard. For noncontact actuating interlock switches, the guard door is linked to the control circuit contacts via a magnetic or electronic field.
Safety Mats
Safety mats are presence-sensing devices used to guard a floor area around a machine or robot.
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Engineering Web: Safety Relays and Control Modules - Machine Design
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Smart trucks
... a central-control module (CCM) coordinates information between CANLink I/O modules that handle load control, safety interlocks, engine-load control, soft limits for devices, programmable limits, and ...
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The Machine Design Tech Insider - July, 2007
The balance of the 1400 pages includes product specifications and selection guides for the following safety products: Light Curtains, Laser Scanners, Mats, Interlocks, Relays, Network Controllers, ...
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