Instructions

Detailed descriptions of I/O modules | Digital counter module UR20-1CNT-100-1DO
141Manual u-remote1432790000/03/02.2014
Additional counter features
Overview
You can set the additional features for the counter listed be-
low by parametrizing the UR20-1CNT-100-1DO:
– Latch function
If a 0-1 edge appears at the latch input, the current count
value is stored in the latch register
– Comparator
By entering a comparison value, the digital output is acti-
vated or a process alarm is triggered depending on the
counter value
– Hysteresis
It is possible to prevent frequent switching of the output
and/or triggering of the alarm, e.g. when the value of a
sensor signal fluctuates around the comparison value, by
setting the hysteresis
The gure illustrates how counting behaviour is affected
by the additional features. These additional features are ex-
plained in the following pages.
HW gate
Internal gate
Comparison value Process alarm
Comparator
Hysteresis
Output
Counting value
Load value
Latch
SWgate Pulse/track A
Pulse evaluation
Direction/track B Latch
Additional counter functions.
Latch function
If a 0-1 edge appears at the “latch” input during a counting
process, the current counter value is stored in the latch
register.
The latch register is accessed through the input range. The latch is
always 0 after a STOP-RUN transition.
Comparison function
The comparison value is preset using the rst double word of
the process data outputs. If the digital output was released
via control word the bit “Comparison condition met” of the
status word is activated as soon as the comparison condition
is met.
The behaviour of the counter output can be determined via
prametrizing:
– Output never switches
– Output switches if the counter value ≥ comparison value
– Output switches if the counter value ≤ comparison value
– Output switches at the comparison value
Output never switches
The output never switches.
Output switches if the counter value ≥ comparison value
The output remains set as long as the counter value is larger
than or equal to the comparison value.
Output switches if the counter value ≤ comparison value
The output remains set as long as the counter value is less
than or equal to the comparison value.
Pulse at comparison value
The output is set for the parametrized pulse duration if the
counter reaches the comparison value.
If the pulse duration = 0, the output remains set until the
comparison condition is no longer met.
If a primary counting direction has been set, the output
switches only upon reaching the comparison value from the
primary counting direction.
Pulse duration
The pulse duration indicates how long the output should re-
main set. It can be preselected between 0 and 522.24ms in
steps of 2.048ms.
The pulse duration begins with the setting of the corre-
sponding digital output. The inaccuracy of the pulse duration
is less than 2.048ms.
If the comparison value is left during a pulse output and
is reached again, there is no post-triggering of the pulse
duration.
The bit “comparison condition met” is activat-
ed together with the bit “DO set” of the status
word. In contrast to the “DO set” bit it remains
active until it is reset with the bit “Reset status
bits” of the control word..