Description; Operation With Disturbed Frequency Input Signals; Resetting To Delivery State - Phoenix Contact MCR-F-UI-DC Handbuch

2. Description

MCR-F-UI-DC, the programmable MCR frequency transducer, is a module for displaying and converting
frequencies up to120 kHz. On the input side, all common frequency generator signals in 2, 3 and 4-wire
technology, and signals from incremental encoders can be collected.
The input impulses are evaluated using period measurement and are then output by a processor as an
analog voltage or current value to match the measuring range start and end value entered.
In order to achieve as short as possible reaction times, the inputs of the frequency transducer have pur-
posely been designed without a frequency input filter. An automatic measurement range selection func-
tion (autorange) ensures that the measured value is always displayed with the optimum resolution.
Frequency interferences can, however, lead to too large a division factor being selected for low input fre-
quencies. This in turn can result in an erratic output signal (see point 3: Operation with disturbed frequen-
cy input signals).
In order to stabilize fluctuating input values, a filter function has been implemented for conversion into the
analog output value. The depth of this filter can be set from 1 to 15 using the membrane keyboard. The
optimum filter depth depends on the application.
In addition to the analog output, there is also a PNP transistor switching output with a maximum carrying
capacity of 100 mA, for monitoring functions, for example (not short-circuit proof).
Specially for rotational speed measurement, it is possible to both enter the measuring range start and end
value in revolutions per minute (RPM), and to observe the revolutions in RPM on the LCD (4-pos. + RPM
as unit) during operation.

3. Operation with disturbed frequency input signals

3.1. Measures to counter external influences
• Use shielded conductors.
• Lay cables in an appropriate manner (EMC-compliant)
• Connect terminal 4 (GND 1) along the most direct route to PE.
3.2. If signal level > 20 V (Fig.2 -
• Unplug the jumper located in the module after opening the side
flap. The jumper can be parked temporarily on one of the three
free pins.
• Now route the frequency input signal to the module via
terminal 2.
The signal is returned via terminal 4 (GND 1).
• No additional settings are necessary.
3.3. If signal level > 10 V (Fig.2 -
• Connect the bottom two pins of the pin strip with the jumper.
• Now route the frequency input signal to the module via
terminal 2.
The signal is returned via terminal 4 (GND 1).
• No additional settings are necessary.

4. Resetting to delivery state

• Connect the top two pins of the pin strip (nearest display) with
the jumper.
• Terminal 2 is now ready again for the connection of NAMUR sensors.
1
)
2
)
3
(Fig.2 - )
1
2
3
Fig.2
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