44
1MRS755225
Transformer Terminal
Technical Reference Manual, General
RET 54_
5.1.7.3.
Pulse counters
Some specific digital inputs (refer to Section “Digital inputs” on page 42) of the
RET 54_ transformer terminal can be programmed either as digital inputs or as pulse
counters. This programming is done via the parameter “Input # mode” (in this
parameter as well as in others mentioned below, # denotes the input number).
When an input operates as a pulse counter, the positive input transitions (0 -> 1) of
a filtered input are counted and the counter value of “Input # counter” increases in
the range 0... 2147483647. The pulse counters are updated with a period of 500 ms.
The frequency range of a digital input parameterized to operate as a pulse counter is
0...100 Hz.
dipo2_b
Fig. 5.1.7.3.-1 Principle of the pulse counter function
The parameter “Input # preset” can be used to give a counter the start value.The start
value is loaded into the counter by:
• Writing the desired start value to the parameter “Input # preset”,
• writing the value 1 to the parameter “Counter trigger”. Then all the updated
values of the “Input # preset” parameters are copied to the corresponding “Input #
counter” parameters.
Writing the value 2 to the “Counter trigger” parameter copies all the “Input # preset”
values to the corresponding “Input # counter” parameters. Writing the value 0 clears
all the counters.
5.1.7.4.
Oscillation suppression
Oscillation suppression is used to reduce the load from the system when, for some
unrecognized reason, a digital input starts oscillating. A digital input is regarded as
oscillating if the number of valid state changes (= number of events after filtering)
during 1 second is equal to or greater than the set value “Input osc. level”
Parameter
Values
Default
Input # preset
0..... 2147483647
0
Input # mode
1 = digital input
2 = counter
1
Counter trigger
0 = clear all counters
1 = load updated Input # preset values
2 = load all Input # preset values
Filtered
Input
Counter
