AnasayfaProductsTransponder-coded read heads with external evaluationCEM read heads

Read heads CEM

Description

With transponder coding
Integrated mounting magnet (without guard lock monitoring)
Up to Category 4 / PL e according to EN ISO 13849‑1 for monitoring the position of the guard
Adjustable adhesive force optional

Design and functionality

A CES read head and a mounting magnet are integrated into the CEM read head. The CEM read head is connected to the CES evaluation unit with a round M8 plug connector. The CEM actuator of identical design also has a metal plate in addition to the transponder; this plate acts as an armature for the solenoid coil. When the safety door is closed, the CEM actuator enters the actuating range of the CEM read head. The transponder signals are transferred, and then the evaluation unit closes the safety contacts and sets the OUT output to High. By applying voltage to the mounting magnet for the CEM read head, strong magnetic forces are generated between the coil (in the read head) and the armature (in the actuator). Depending on the version, locking forces of approx. 650 N or 1,000 N are applied between the CEM actuator and the CEM read head. Practical experience has shown that these magnetic forces effectively prevent any opening, even if the user applies considerable effort.

Use of the read head even in extremely harsh environments

The read heads CEM have an extremely robust design. The high degree of protection IP67 and the metal housing allow the read head to be used in extremely harsh environments. The armature plate for the CEM actuator has spring mountings and can be deflected up to an angle of ± 4°. Therefore, when a misadjusted safety door is closed, the CEM actuator adjusts itself independently to the surface of the CEM read head. It is not necessary to readjust the safety door when using the read heads CEM. When mounting the read head CEM, it is necessary only to ensure that the CEM actuator is guided in front of the CEM read head when the door is closed, so that the strong adhesive forces can be generated.
Because the read head has only a small number of moving parts that can wear, the mechanical life of the CEM read heads is virtually unlimited.

Different versions

EUCHNER provides two CEM housing designs. The two versions differ in their dimensions, according to the size of the solenoid. The safety switch CEM with a locking force of 1000 N is used with large, heavy safety doors. This read head has an additional M8 plug connector for the connection of an external LED display. When voltage is applied to the coil, it is indicated to the user that the safety door is in the locking position. A display close to the door handle is of advantage particularly for large, massive doors.
The smaller version of the read head CEM has a locking force of approx. 650 N. It is suitable for securing smaller safety doors and safety flaps.
An LED indicator in the M8 male socket on the read head indicates to the user when voltage is applied to the solenoid.

With or without remanence

In particular during metal machining, the residual magnetism (remanence) in the guard locking solenoid can cause problems. In the open state, metal chips may be drawn to the contact area. The next time the guard is closed, there will be a gap between the actuator and read head that will limit the locking force. To avoid this effect there are read heads without remanence. These are demagnetized when the guard is opened such that metal chips adhering to the surface fall off.

Adjustable adhesive force

This version has an adhesive force also with the guard locking switched off. In this way it is intended, for example, to prevent the safety door from opening due to vibration or similar. The adhesive force can be adjusted using a programming adapter to 30 N, 50 N or 80 N.

Benefits for you

Safety switch with transponder coding
Every actuator is unique
Maximum protection against tampering
Integrated solenoid for process protection
Unintentional opening of the safety door is prevented
Safety switch and solenoid form a compact unit
High solenoid locking forces (650 N or 1000 N)
Protection of the machining process.
Simple principle of operation. No wearing parts.
Robust housing for harsh environments
Connection via M8 plug connector
Less wiring work
Easy to replace if servicing is required

Approved by employers’ liability insurance association and UL (Canada and USA)
Important: The device is allowed to be used as guard locking only if there is no hazard due to overtraveling machine movements. The guard locking is used only for process protection.