Function description
Operating Manual PSSu E S INC 24V se(-T)
1001380-EN-04
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}
b: At the next rising edge at channel A, the counter counts backwards because there is
a 1 signal at channel B.
}
c: The counter is disabled because there is a 1 signal at input C.
}
d: The module has received a latch pulse. Provided the function is activated, the
counter value is copied into the latch memory with a rising edge at input L.
}
e: The counter is disabled because there is a 1 signal at input G.
4.2.5
Functions
4.2.5.1
Measure period length
The module can record the period length of the counter pulses on channel A. The period
length is the time between two rising edges at channel A. It is transferred to the process im-
age of inputs as multiple of 200 ns.
Prerequisite: This function is configured in the PSSu Configurator / PAS4000.
PIO
PII
Legend:
}
PIO: Bit 1 of the function call in the process image of outputs or I/O data Output-
Data.LatchOrMeasure
}
PII: Bit 1 of the status byte in the process image of inputs or I/O data InputData.Lat-
chOrMeasureDone
Key to timing diagram:
Section Function
Procedure for PSSu in sys-
tem environment A
Procedure for PSSu in sys-
tem environment B
a
Start measure-
ment
In the user program, set Bit 1
of the function call
In the user program, set Out-
putData.LatchOrMeasure
b
Output measured
value
Set status bit
Measured value is trans-
ferred into the process image
of inputs
The module sets Bit 1 of the
status byte
Measured value is written in
InputData.LatchOrPeriod
The module sets Input-
Data.LatchOrMeasureDone
c
Finish measure-
ment
In the user program, reset Bit
1 of the function call
In the user program, reset
OutputData.LatchOrMeasure
d
Ready for new
measurement
The module resets Bit 1 of
the status byte
The module resets Input-
Data.LatchOrMeasureDone
The result of the last period length measurement remains in the process image of inputs
until the module signals a new measurement result by setting the status information. Before
the initial measurement the process image of inputs contains 0000 0000
H
or FFFF FFFF
H
