Non-contact safety switch CES-A-C5.../CES-A-W5.../CES-A-S5...

Functional Description

The Coded Electronic Safety switch CES comprises two components:

• Coded actuator
• Evaluation unit / read head

The evaluation unit described in this section is integrated with the read head in a standard housing according to IEC/EN 60947-5-2.

Thanks to the high degree of protection IP67, this switch can be used directly on the safety guard in a very harsh environment. Semiconductor technology allows for a compact design of the evaluation unit and wear-free switching with a theoretically unlimited number of operating cycles.

The information from the coded actuator is read by the evaluation unit and processed at the same point. The transfer of static signals (information on whether door open or closed) to the higher level switchgear permits the use of connecting cables up to 300 m long with the system. Serial wiring, i.e. the cascading of several evaluation units, is possible. This feature makes it possible for you to implement decentralized wiring concepts with the safety switch CES.

Specifically, the major advantage of the system is that the positioning of the evaluation unit directly at the safety guard saves space in the control cabinet.

The system operator can read the current state of the safety switch on the two LED indicators (one with double function). If the actuator is in the operating distance, the OUT LED illuminates yellow. Even a possible fault in the evaluation unit is indicated by a red LED. In service, the safety switch connected with an M12 plug connector can be replaced in seconds. The required approach direction can also be set quickly on the compact housing. After two fastening screws have been undone, the active face of the read head can be set in 5 different positions.

The safety switches have a relatively large operating distance of 20 mm. Compared with mechanical safety switches, the assembly of the unit is much easier and the need for precision in the door rails is also reduced considerably. Therefore the assembly and maintenance costs are much lower.

The safety switch with integrated evaluation unit and read head is fastened to the fixed part of the safety guard. The actuator attached to the movable part of the safety guard is moved towards the read head fitted in the safety switch by closing the door. When the switch-on distance is reached, power is supplied to the actuator by the inductive read head and data can be transferred.

The bit pattern read is compared with the code saved in the evaluation unit; if the data matches, the safety outputs (semiconductor outputs) and the monitoring output (semiconductor output) are also set HIGH.

Due to the combination of dynamic polling of the actuator and the redundant, diverse design of the safety electronics with the two feedback safety outputs, the evaluation unit will enter the safe state with every detectable fault.

When the safety guard is opened, the safety outputs switch off the safety circuit and the monitoring output (OUT) is switched LOW. The state of the safety outputs is monitored internally by two microprocessors.

On an internal fault in the evaluation unit, the safety circuit is switched off and the OUT/ERROR LED illuminates red. The evaluation unit has a redundant switching design with self-monitoring. This means that the safety system is still effective even if a component fails.

Switching pulsed signals

The safety outputs can switch pulsed signals, e.g. from a safe control system or a safety relay. Up to three safety outputs can be connected in series.

Connection example CES-A-C5.../CES-A-W5...

Non-contact safety switch with position sensor CES-A-S5...

The safety function is identical to that of the safety switch CES-A-C5H-01. The position actuators have a fixed transponder number from 2 to F (hex). Up to a maximum of 15 different actuators can be used per device: 1 safety actuator (red) and 14 different position actuators (green).

For position actuators the related transponder number is output to a higher level control system on the four semiconductor outputs (D0, D1, D2, D3) as a 4-bit binary code. The four LEDs (D0, D1, D2, D3) on the device indicate the status of the semiconductor outputs (D0, D1, D2, D3).

Connection example CES-A-S...

The CES-A-S... safety switch and position sensor with only one device

The CES-A-S... series has a position sensor along with the safety function. The position sensor has no safety function and is therefore not allowed to be used for safety-related polling.

The non-contact safety switch CES-A-S... consists of the following system components:

• 1 coded safety actuator
• Up to 14 coded position actuators (dogs)
• Safety switches

Your advantages

• Relocation of the evaluation unit from the control cabinet to the system
• Connection to safe control systems
• Serial connection of up to 3 devices in succession
• Connection via M12 plug connector
• Easy adjustment of the read head in 5 approach directions
• Short circuit-proof monitoring and safety outputs
• Large operating distance of 20 mm with additional hysteresis
• Large mechanical tolerances possible for door guide
• Flush installation in door panel is possible
• Approved by BG and UL (Canada and USA)