Function description
Operating Manual PNOZ m EF 8DI2DOT
1004649-EN-03
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4.2.2
2-pole outputs
The expansion module provides two dual-pole outputs.
Features:
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Signals at the output
– "0" signal (0 V) at the output (O+/O-):
Output is high impedance
No current to the load
– "1" signal (+24 V) at the output (O+/O-):
Output is low impedance
Current is supplied to the load
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The max. capacity at an output depends on the load (see drawing on the max. capacitive
load). Connecting a higher capacity may lead to an error.
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Operation with electronic contactors has not been tested and may lead to errors. Please
contact our Customer Support team if you are using electronic contactors.
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Open circuit detection
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Cannot be used as a single-pole output
Output tests
The following output tests are carried out:
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Asymmetric test in error-free operation
– In this test, one output transistor is switched on and the other switched off for the test
duration t1 as a maximum. The load is not switched on because of the test. If errors
are detected during this test, then an advanced on test is run.
– The test duration t1 is max. 5 ms.
– The repetition time between the asymmetrical tests t2 is at least 30 s.
– The time t3 between two asymmetrical tests O+ and O- is at least 1 s.
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Advanced on test in the event of an error
– The advanced on test is always run directly after an asymmetric test, in which an er-
ror has occurred. It is used to determine the cause of the error.
– The test is run for the test duration t1 as a maximum
– The test duration t1 is max. 5 ms.
– The test enables precise error diagnostics
– The load must not switch on because of the test.
– The following errors are detected:
Shorts across contacts (external error),
Short circuits and interruptions on the transistors,
Short circuits and open circuit on the connected load
