MMF VS11 User manual

Instruction Manual
Manfred Weber
Metra Mess- und Frequenztechnik in Radebeul e.K.
Meissner Str. 58 - D- 1445 Radebeul
Tel. [phone] Fax [phone]
Email: [e-mail] Internet: www.MMF.de
Vibration Switch/
Sensor
VS11
VS12

Editor:
Manfred Weber
Metra Mess- und Frequenztechnik in Radebeul e.K.
Meißner Str. 58
D-0 445 Radebeul
Tel. [phone]
Fax [phone]
Email [e-mail]
Internet www.MMF.de
Note: The latest version of this manual can be found as a PDF at
http://www.mmf.de/produktliteratur.htm
Specifications subject to change.
© 20 6 Manfred Weber Metra Mess- und Frequenztechnik in Radebeul e.K.
Full or partial reproduction subject to prior written approval.
Nov/ 22 # 94

Inhaltsverzeichnis
.Application.............................................................................................................4
2.The Devices at a Glance.........................................................................................4
3.Connectors..............................................................................................................5
3. .Power Supply..................................................................................................5
3.2.Relay Output...................................................................................................5
3.3.USB Interface..................................................................................................6
4.Parametrization.......................................................................................................6
4. .Device Identification.......................................................................................6
4.2.Settings............................................................................................................7
4.2. .General.....................................................................................................7
4.2.2.Monitoring Mode.....................................................................................7
4.2.3.Gain.........................................................................................................7
4.2.4.Filters and Integrators..............................................................................8
4.2.5.Warning and Alarm Limits.......................................................................8
4.2.6.Switching Output.....................................................................................8
4.2.7.Factory Settings / Calibration...................................................................9
4.3.LED Status Indicators.....................................................................................9
5.Measuring in the Time Domain..............................................................................9
6.Measuring in the Frequency Range (FFT)............................................................
7.Teach-in Function................................................................................................. 2
8.Measuring Points on Rotating Machines.............................................................. 3
8. .General.......................................................................................................... 3
8.2.Attachment.................................................................................................... 3
8.3.Attachment Recommendations to ISO 08 6- ............................................ 3
9.Vibration Monitoring with Standard Limits.......................................................... 4
0.Installing the PC Software.................................................................................. 7
.Integration of VS / 2 with other Software....................................................... 8
2.Firmware Update................................................................................................ 8
3.Technical Data....................................................................................................20
Appendix: Warranty
CE Declaration of Conformity

Thank you for purchasing a Metra product!
1. Application
The VS / 2 vibration switches are designed to monitor vibration amplitudes on ro-
tating machines (see. Chapter 9). When a given amplitude is exceeded an alarm sig-
nal or automatic shutdown is triggered via the relay output. Similarly, the devices
can be used as impact detectors, for example, to report collisions.
The VS and VS 2 devices measure and monitor vibration in both the time and
frequency domain, for this reason they can selectively monitor individual frequency
band components.
The devices possess a piezoelectric precision accelerometer and micro-controller-
based electronics. This ensures high reliability and reproducibility. The devices are
configured via a USB interface and free software. Due to its wide range of settings
VS / 2 can be adjusted to every application, from the measurement of low vibra -
tions to the detection of high-frequency shock accelerations.
2. The Devices at a Glance
VS :
VS 2:
4

3. Connectors
3.1. Power S pply
The VS vibration switch operates with DC voltage in monitoring mode, the termi-
nals "+ U" (positive) and "0V" (negative/ground) must be connected inside the cas-
ing. The supply voltage range is 5 to 30 V. Power consumption is less than 00 mA.
During parameter setting the VS obtains its power via the USB cable.
The VS 2 is powered by connecting a USB cable to the 8-pin socket. Alternatively,
a DC voltage of 5 to 2 V can be connected at the terminals 4 (positive pole) and 7
(minus/ground) of the 8-pin socket (Figure 2).
The supply voltage connection is protected against false polarity.
3.2. Relay O tp t
The devices contain a PhotoMOS relay. The relay switching behavior can be pro -
grammed with the VS x software (see. Chapter 4.2.6.). The relay terminals are gal-
vanically isolated from the rest of the circuit.
The VS relay output is connected via screw terminals inside the housing (Figure
).
VS 2 has relay terminals located at contacts and 2 of the 8-pin socket (Figure 2).
Metra offers connection cables for VS 2 with an 8-pin connector for power supply
and relay output.
Please note that the relay is only suitable for switching small loads (see. Chapter
Technical Data). No overload protection is provided.
5
Figure 2: Outside view of the VS 2 socket with terminal numbers
Figure : Open VS with terminals for power supply / relay output and USB socket

3.3. USB Interface
For setting parameters and measuring, the devices have a USB 2.0 interface in full-
speed mode and CDC (Communication Device Class). VS is connected via a stan-
dard micro USB socket inside the casing (Figure ). The VS 2 USB port is located
on the 8-pin socket (Figure 2). The contacts are assigned as follows:
Pin 6: +5 V
Pin 3: D+
Pin 5: D-
Pin 7: Weight
The VS 2-USB cable is provided for connection to a PC.
When connecting the vibration switch to a PC via USB, the device is powered by
the interface. In this case an additional power supply may not be used.
4. Parametrization
4.1. Device Identification
To setup VS / 2 open the LabView application vs x.vi. Notes on installation are
provided in Chapter 0. The program opens in the setup view (Figure 3).
The VS / 2 runs in virtual COM port mode, i.e. the device is assigned a virtual
USB serial port (COM port). The COM port number is assigned to the device by
windows, but can be changed in the windows control panel if required.
The COM port number is displayed under “Setup” in the top left corner. If the
VS / 2 was already connected when the program started, it will be automatically
recognized. Otherwise, you can start the search manually by clicking on "Search
6
Figure 3: Setup View

VS x". The computer then searches from the entered COM port number and ends
with COM50. You can also manually change the COM port. This may be useful if
several VS / 2 are connected to the computer at the same time. The program
works with COM port numbers to 50.
On the top right you will see a status bar. If the green framed “OK” signal is shown
the connection has been established. If the connection is interrupted the red framed
“ERROR” signal will be shown.
4.2. Settings
4.2.1. General
The current settings are read as soon as the device is detected. In the line next to the
COM port number you can see the type, version (3 digits for hardware and 3 digits
for software), serial number and date of last calibration. This information cannot be
edited. The device name can be overwritten and transferred to the device by press-
ing “Enter”.
Press the “Save” button to save the settings as an XML file and “Load” to upload
them into the program. The adjustable parameters are assigned to the function
blocks “Gain”, “Filters/Integrators”, “Warning”/Alarm” and “Switch Output”.
All entries will immediately be transferred to VS / 2 and retained even after dis-
connecting the supply voltage.
4.2.2. Monitoring Mode
VS / 2 has two monitoring modes to choose from:
•Monitoring in the time domain with RMS and peak values (see Chapter 5.)
•Monitoring in the frequency domain with frequency-band-dependent limit values
(see Chapter 6.)
Select the mode under “Monitoring”. The most recently selected mode and the cor-
responding limits will remain active after closing the program or interrupting the
USB connection. The same applies to the teach-in function (see. Chapter 7.).
4.2.3. Gain
The gain can be selected from values , 0 and 00 via the “Fix” menu. The “Auto”
setting automatically selects the most appropriate gain range. In this case the gain
menu is grayed-out.
Most monitoring tasks can be carried out using automatic gain (auto). It is advanta-
geous because it achieves a better resolution when measuring low vibration ampli-
tudes at higher gain levels. On the other hand unexpected high amplitudes do not
cause overload.
There are, however, applications for which automatic gain selection is inappropriate,
for example, at amplitudes that constantly fluctuate around a switching point or fre -
quent single shocks.
7

4.2.4. Filters and Integrators
VS / 2 can monitor vibration acceleration or vibration velocity. A range of high
and low pass filters are available for selection. The widest frequency range is 0. Hz
to 0 kHz for acceleration, and 2 to 000 Hz for velocity. The frequency range is
adjusted via a drop-down menu. The three vibration velocity ranges can be found at
the end of the menu. For information on customary frequency ranges in monitoring
rotating machinery, see Chapter 9..
Setting the filters and integrators is only relevant when monitoring in the time do-
main (RMS and peak). In the FFT mode they are deactivated.
4.2.5. Warning and Alarm Limits
You can select the monitoring value from the “RMS/Peak” menu. RMS values are
typically used for measuring vibration, and peak values for single impacts.
The alarm limit determines the switching threshold of the relay output. It is entered
in m/s² for acceleration or mm/s for velocity. The permissible value range is 0. to
500.0.
The warning limit is entered as a percentage of the alarm value.
Values ranging from 0 to 99% are permissible. The warning limit can be used to
indicate pre-alarm status via the LEDs before the alarm is triggered (see Chapter
4.3.).
The “teach-in-factor” is an automatic measuring function for the alarm limit (see
Chapter 7.). It determines how far the alarm limit is set above the currently mea-
sured maximum value. The teach-in warning limit is always set at 50%.
It is only necessary to preset the monitoring variables and the alarm limit when mea-
suring in the time domain (RMS and peak). In FFT mode the alarm limit is set in the
FFT window (see Chapter 6.).
4.2.6. Switching O tp t
The VS / 2 contains a PhotoMOS relay switch. The switching function can be
specified in the options menu. The relay opens (n.c.) or closes (n.o.) in response to a
warning or alarm signal.
The power-on delay is the delay between switching on the power and activation of
the monitoring function. It helps prevent false alarm signals after switching on the
device caused by the transient response of the signal processing.
The delay range is 0 to 99 seconds.
The power-on delay is the delay between the alarm threshold being exceeded and
the relay switching. At zero the relay reacts immediately.
If a minimum time duration should apply to exceeding the alarm limit, a switching
delay of up to 99 seconds can be entered.
The “Hold time” is the time when the amplitude falls below the alarm limit until the
relay returns to normal status. This setting can be useful if a minimum alert duration
is required. The range is from 0 to 9 seconds.
8

4.2.7. Factory Settings / Calibration
By clicking the “Set defaults” button all parameters are restored to factory settings
(acceleration 2- 000 Hz, automatic gain, limit value 0 m/s², pre-alarm to 50%,
teach-in factor 2, relay close when alarm is triggered, switching delay 0 s, alarm
delay 0 s, hold time 2 s).
The calibration password (“Cal. Password”) only needs to be entered by calibration
labs.
4.3. LED Stat s Indicators
The VS signalizes the current status via four green/red LEDs. Whenever the de-
vice is ready for operation all LEDs light up. The LEDs have the following configu-
ration:
4 x green: no warning / no alarm
2 x green/ 2 x red: warning limit exceeded
4 x red: alarm limit exceeded
The LEDs show the current vibration level in relation to the limit values.
They may differ from the current switching status of the relay if the switching delay
or the hold time has not yet elapsed.
5. Meas ring in the Time Domain
Besides vibration monitoring with switch output, theVS 2 can be used in conjunc-
tion with PC software to record and display RMS and peak values with the selected
filer and integrator settings.
For this purpose switch to the tab “RMS/Peak”. The upper window contains the nu-
merical display for RMS and peak. The time chart plots the course of the vibration
quantity selected under “Plot” (Figure 4).
9
Figure 4: RMS /Peak Measurement

The value axis label shows the vibration quantity and the selected filter. The time
axis adjusts to the duration of the recording. By right-clicking in the chart area (Fig-
ure 5) you can automatically scale the chart (auto-scaling X/Y). Furthermore you
can select the update mode (Figure 6).
•Strip chart: data is displayed continuously from left to right. A strip chart is simi-
lar to a chart recorder (Y/t recorder).
•Scope chart: shows a signal (e.g. an impulse) periodically from left to right. Each
new value is added to the right of the preceding one. When the graph reaches the
right edge of the display area it is completely erased and redrawn from left to
right. The display is similar to that of an oscilloscope.
•Sweep chart: is similar to a scope chart with the exception that the old data on
the right side is separated by a vertical line from the new data on the left. When
the plot reaches the right edge of the display area it is not deleted but continues
to run. A sweep chart is similar to an ECG display.
The three update modes only effect the visible time interval of the chart. All data
measured since opening the window, including the data which is not visible, is still
accessible. To view the data use the scroll bar below the chart.
The three update modes only work if “Auto-scaling” has been deselected (Figure
5).
The chart axes can be manually rescaled by double-clicking on the numerical value
of the axes label and overwriting the value.
Under “Export” you will find the following options:
•Copy chart data as value table to clipboard
•Copy chart graph to clipboard
•Open chart data in an Excel table (if Excel has been installed)
These export options can also be found as buttons next to the chart.
Press the “Stop” button if you wish to cancel the recording. The display will pause.
By pressing “Restart” the chart is deleted and begins anew.
6. Meas ring in the Freq ency Range (FFT)
In addition to monitoring RMS and peak, VS and VS 2 enable limit value moni -
toring in the frequency range by means of frequency analysis (FFT). The vibration
spectra can be viewed in conjunction with the PC software.
0
Figure 5: Chart Menu
Figure 6: Update Mode