User manual

6 Detailed descriptions of I/O modules | Digital counter module UR20-1CNT-100-1DO
344 1432790000/08/12.2015Manual u-remote
Additional counter features
You can dene the additional features for the counter listed
below by parameterising or via the process data outputs:
– Reset: resets the counting value to the load value during
counting.
– Latch function: stores the current counting value in the
latch register.
– Comparator: Upon meeting the comparison condition,
the digital output is activated or a process alarm is trig-
gered.
– Hysteresis: reduces frequent switching of the output and/
or excessive triggering of process alarms, e.g. when the
value of a sensor signal fluctuates around the comparison
value.
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 LatchReset
Release
Additional counter functions.
Reset
The load value will be load into the counting value once the-
re is a signal at the reset input. To use this feature you have
to release the reset mode in the control word (bit QX8.0) in
addition to the parameterisation.
The status bit IX8.3 indicates that there is a signal at the
reset input. Once a reset is done, the status bit IX8.0 is set.
This bit will be reset by deactivating the reset mode (control
bit QX9.0).
Latch function
If a 0-1 edge appears at the latch input, the current counter
value is stored in the latch register. The latch register is ac-
cessed through the process data inputs. With every activation of
the counter the latch value is set to 0.
Comparison function
Via the parameter „Condition for DO“ you can deactivate the
output („never switching“) or dene a comparison condition
for the output‘s switching:
– Counter value higher or equal comparison value
– Counter value lower or equal comparison value
– Counter value equal comparison value
To use the comparison function, you have to preset the com-
parison value in the rst double word of the process data
outputs and release the digital output via the control word
(bit QX8.1).
The bit IX9.1 “Comparison condition met” of the status word
is activated as soon as the comparison condition is met. The
output switches and remains set as long as the comparison
condition is met accordingly to the parameterised hysteresis
and pulse duration.
When using „Counter value equal comparison value“ the
output remains set during the pulse duration parameterised.
With pulse duration = 0, the output remains set until the
comparison condition is not met any more. When using a
counting mode with primary direction, the output will be
switched only upon reaching the comparison value from the
primary direction.
Pulse duration
Via the parameter “Pulse duration” you can determine how
long the digital output should remain set. The pulse duration
can be preselected between 0 and 510ms with an inaccura-
cy of less than 2.048ms. With pulse duration = 0 the output
behaves exclusively according to the comparison conditions.
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.