Oldham MX62, User Manual

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Page 30
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During replacement of the defective module disturbances on the
output bus are possible, e.g. relays of other relay modules can be
affected and switch.
3.4.7. General alarm suspension
The general alarm suspension is a special case of the channel depended
alarm suspension. If activated, all channels are in the operation mode
alarm suspension , independent of the position of the rotary switch at the
CM.
For activation of the general alarm suspension two analog input channels
are needed. The two channels have to be configured in a special manner
by the software
ConfigPro .
The general alarm suspension is activated when both special configured
channels have an alarm.
The general alarm suspension is deactivated when both special configured
channels have no alarm.
Configuration of the analog inputs:
A key switch with two independent contact pairs is needed.
When not switched (position 0 ), on both channels a signal current of 4
mA will be simulated using a 6k resistor.
In the switched position (position 1 , general alarm suspension activated)
at one channel a signal of 8 mA will be simulated using a 3k resistor and
at the other channel a signal of 14 mA using a 1k7 resistor.
ATTENTION!
Only authorized and instructed persons are allowed to use the key switch.
It is not allowed to connect gas detectors to the channels for general alarm
suspension!
3.5. Single mode
In this mode, full redundancy is no longer given or comparison of the two
controllers with each other is disturbed. Measurement will still be done correctly
and all safety functions are maintained. In particular, switching of relay outputs
is guaranteed. Since channel indication on the LED modules and the LCD
module is linked to one of the two controllers, information will not be available
if the respective controller is faulty (see chapter 3.7).
ATTENTION!
If WinPro
®
/ MX62 changes into single mode, immediate measures must be
taken to cancel redundancy loss.