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Subject to technical modififications; no responsibility is accepted for the accuracy of this information
© Bihl+Wiedemann GmbH
Internet: www.bihl-wiedemann.de • Flosswoerthstr. 41 • D-68199 Mannheim
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AS-i Safety Relay Output Module with Diagnostic Slave
1 EDM- and 2/1 safety inputs
Safety Requirements
7.
Safety Requirements
•
The device uses two redundant, force-guided relays.
•
The module recognizes if one of the relays does not switch (for instance if the
contacts are welded).
•
The contact sets 1.13/1.23 and 1.14/1.24 use the same relay; they do not
operate independently.
•
The contacts 1.13, 1.23, 1.14, 1.24 are potential-free. A cross-short check is
not available.
•
If the device is set up to control two independent safety contactors, the con-
nection between the safety contactors and the device must never be sub-
jected to another potential as this could result in the inadvertent activation of
the safety contactors.
•
Input 1.Y1 is a standard AS-i input.
•
The external 24 V supply must be provided by a PELV power supply.
•
Normally open switches must be connected to S1 and S2
7.1
Requirements for use in a Safety Category 4 environment
Safe turn-off must be checked at regular intervals (a recommended value is
3 months).
Use of a mechanically positive-opening switch together with a protected cable
routing requires no cyclical test of the input functionality according to EN 954-1,
cat. 4.
7.2
Recommendation for improved availability of the function
The switching contacts should be turned off for at least 41 ms, since the safety
monitor (depending on the set monitoring component) must recognize the INPUT
OFF for a minimum number of AS-i telegrams. IF the minimum off time of 41 ms
(depending on the number of slaves on the AS-i bus and the set monitoring com-
ponent) is maintained, correct recognition of the input state is assured. Non-ob-
servance of this time may limit the availability of the AS-i Safety Monitor as fol-
lows:
•
A setting of TWO-CHANNEL POSITIVE OPENING can cause the Safety
Monitor to go into the error state; to eliminate the error state, the supply volt-
age for the Safety Monitor must be disconnected.
•
A setting of TWO-CHANNEL DEPENDENT means the Safety Monitor allows
release only after a sufficient off-time; the release can be achieved if the
switching contacts are turned off for at least 41 ms .
Summary of Contents for BWU2236
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