|
Connection with test monitoring units TNT 33 and TMC 66
In contrast to Type 4 protective devices, the protective effectiveness of a Type 2 sensor is checked only at the moment of testing. During the functional test, a test signal simulating an interruption of the protected field is sent to the ECO transmitter. The response of the receiver is then checked to ensure it switched off in time. For safety level Type 2 according to EN-, IEC 61496-1, a loss of protective function is tolerated between the test periods. The time intervals at which this periodic testing must be performed depends on the particular application. Support is provided in this regard by the BG (Berufsgenossenschaft) expert committees responsible for machine safety.
The Leuze lumiflex test monitoring units TNT 35 and TMC 66 (with muting integrated) or the MSI-interfaces represent an optimal solution for this task. Regardless of the machine cycle, both test monitoring units monitor the protective effectiveness of the sensors every 2 seconds, without interrupting the production sequence of the safeguarded machine. Due to this rapid succession of cyclical functional tests, a maximum of Type 2 functional safety is achieved.
In addition, the functional range of the ECO is expanded by this devices, adding "start/restart interlock" and "relay monitoring" functions.
|
