3.13 Parameter Subset Selection (Function Group PSS)
With the P634, four independent parameter subsets may be pre-set. The user
may switch between parameter subsets during operation without interrupting the
protection function.
Selecting the Parameter Subset
The control path determining the active parameter subset (function setting or
binary signal input) may be selected via the function setting PSS: Control via
USER or via the external signal PSS: Control via user EXT. Correspondingly,
the parameter subset is selected either in accordance with the pre-set function
setting PSS: Param.subs.sel. USER or in accordance with external signals.
Which parameter subset is actually active at a particular time may be
determined by scanning the logic state signals PSS: Actual param. subset or
PSS: PS 1 active.
Selecting the Parameter Subset via Binary Inputs
If the binary signal inputs are to be used for parameter subset selection, then the
P634 first checks to determine whether at least two binary inputs are configured
for parameter subset selection. If this is not the case, then the parameter subset
selected via the function setting will be active. The P634 also checks whether the
signals present at the binary signal inputs allow an unambiguous parameter
subset selection. This is only true when only one binary signal input is set to a
logic level of “1”. If more than one signal input is set to a logic level of “1”, then
the parameter subset previously selected remains active. Should a dead interval
occur while switching between parameter subsets (this is the case if all binary
signal inputs have a logic level of “0”), then the stored hold time is started. While
this timer stage is running, the previously selected parameter subset remains
active. As soon as a signal input has a logic level of “1”, the associated
parameter subset becomes active. If, after the stored time has elapsed, there is
still no signal input with a logic level of “1”, the parameter subset selected via
the function parameter becomes active.
If, after the supply voltage is turned on, no logic level of “1” is present at any of
the binary signal inputs selected for the parameter subset selection, then the
parameter subset selected via the function parameter will become active once
the stored time has elapsed. The previous parameter subset remains active while
the stored hold timer stage is running.
Parameter subset selection may also occur during a starting condition. When
subset selection is handled via binary signal inputs, a maximum inherent delay of
approximately 100 ms must be taken into account.
Settings for which only one address is given in the following sections are equally
effective for all four parameter subsets.
P634
3 Operation
3-100 P634/EN M/R-42-A // P634‑311‑653
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