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4-24
Supporting Functions
Timers
857-UM001A-EN-P – July 2009
The Allen-Bradley protection platform includes four settable timers
that can be used together with the user's programmable logic or to
control setting groups and other applications that require actions
based on calendar time. Each timer has its own settings. The selected
on-time and off-time is set and then the activation of the timer can be
set to be as daily or according the day of week (See the setting
parameters for details). The timer outputs are available for logic
functions and for the block and output matrix.
Figure 4.9 – Timer Output Sequence in Different Modes
The user can force any timer, which is in use, on or off. The forcing
is done by writing a new status value. No forcing flag is needed as in
forcing i.e. the output relays.
The forced time is valid until the next forcing or until the next
reversing timed act from the timer itself.
The status of each timer is stored in non-volatile memory when the
auxiliary power is switched off. At start up, the status of each timer
is recovered.
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