Testing With Connection Options - ASO Safety Solutions ISK 77 Série Mode D'emploi

9.3 Testing with connection options

For the design of the protection to conform to engineer standards (categor�� 2 with external test
request), the protection must be tested prior to each dangerous movement or during the non-
dangerous phase/movement of the machine. The test is intended to ensure the proper function of
the safet�� rela��. After appl��ing the test signal, the control output must deactivate. This change in
switching state must be evaluated b�� the primar�� machine control. If the test result is correct, the machine
control then initiates the movement or the next work step. Otherwise, the controller must output an
error message and prevent a dangerous movement. If the machine control detects an error fault in
the safety device, the machine control must maintain a safe state until the error is rectified.
Test signal
Output (active)
(inactive)
B�� appl��ing an external voltage (value range 20 to 35 volt DC, 20 to 28 volt AC), an externall�� requested
test is performed according to the selected mode.
U
test
Upon actuation of switch sw, the test is requested and results in the deactivation of the outputs.
Without testing, the operation or wiring of device variant ISK 77 RT satisfies no
specific safety requirements.
9.4 Special feature of the safety-related semiconductor outputs (OSSD)
The electronic safet��-related semiconductor outputs of the switching unit are constantl�� tested during
running operation. For this purpose, the output is c��clicall�� switched off ever�� 0.4 seconds for a period
less than 1 ms and the shut-down behaviour tested. These interruptions must not be evaluated b��
the higher-order controller as safet�� requests.
A primar�� controller should onl�� evaluate the states of the output signal if the level is sustained for
5 ms. This prevents pulses generated during a self-test while in the switched-on state and the testing
of the switch-on procedure from erroneousl�� being processed as control information.
< 10 ms
sw
TST-SIG
TST-MOD
TST-COM
>25 ms
< 50 ms
sw
U
test
TST-SIG
TST-MOD
TST-COM
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