06-27-2006 01:58 AM
06-27-2006 08:33 AM
06-27-2006 08:36 AM
If you decide to use two of the 9215 modules, instead of one 9205, you can get a bnc version of the 9215, 9215bnc, and get in-line attenuators from pomona, http://www.tequipment.net/Pomona4108.asp. THis is probably the less hassle option.
06-28-2006 05:59 AM
06-29-2006 03:30 PM
An attenuator is simply a voltage divider. It scales the voltage from +/- 30V to +/- 10V, in the case of the 10db attenuator. You could also provide your own voltage divider.
10-12-2007 11:54 AM
I am using a Bently 3300 system to monitor machinery health on a rotating equipment test bed.
The Bently rack is monitoring vibration (gear shaft positions via prox probes and gear mesh vibration via acceleromter) and bearing temperatures.
I use an interface application, built with the LV MODBUS library, to gather steady values from the rack, via the system monitor.
At the same time, we are recording the dynamic signals from the buffered outputs, on the front of the Bently monitor modules, using 4472 cards.
I am not as familiar with the 3500 series system, but if it is similar to the 3300 as I am led to believe, you should be able to configure it to store and transfer dynamic content of the channels' signals if you have installed the correct sysmet monitor module. We opted out of that approach, because we wanted to be able to record the dynamic data continuously, and with higher bandwidth than I thought was available through the Bently Dynamic Data Interface, version of the System monitor module. The DDI allows the transfer of snippets of stored dynamic data, rather than a continuous stream. Also, the DDI should have at least a 38.4kb/s maximum baud rate, as does the one in the 3300 system. The Serial Data Interface (SDI) option is of course much slower and has a maximum baud rate of 19.2 kbps as the data set is much more limitted in size.
Again, if the 3500 modules are similar to the 3300 modules, you can configure the input range of the modules thus adjusting the relative amplitude of the displayed values and in turn the steady values. Likewise, you can configure the display, to a certain extent, to display either displacement or velocity for proximitor monitors, and for peak or peak-to-peak units, as well as inches or mm.
If your monitor modules have buffered outputs on the front (or back) panel, they are certainly not configurable. Preston's comments about amplitude and scaling (as well as his other comments on this) are good. The other thing to think about is whether the buffered outputs are DC coupled or AC coupled. (In other words, do they carry through the -DC offset of the proximitors.) If the -7 to - 14 VDC offset is not seen in the buffered outputs, and the standard proximitor calibration of 200 mV / mil (in*10^-3) or 7.87 V / mm, then there is a low probability that you would over-range your input channel(s) and still have much of your pump left to look at, unless it is a really, really big vertical turbine pump.
Another thing to beware of is that you connect any external DAQ channel or other recording device to the buffered outputs of your 3500 monitors. If you were to connect in parallel to proximitor signal where it is fed into the 3500 rack, you risk damaging the rack and / or corrupting your data.
I hope that is helpful.
Dave
09-27-2013 07:24 AM
Dear sir
I am facing difficculty in getting the output from a proximity sensor (Bently Nevada 3000 series) as this type of proximitors are obselote. Please, can you help me out anything about this system so that i can sort out my problem
09-27-2013 10:31 AM
Are you having a hardware problem with the sensors, proximeters, or monitoring rack?
Or a problem connecting a signal from the monitoring rack to your PC using DAQ hardware and LabVIEW?
Please provides some details. Saying "I am facing difficulty" does not provide any information.
09-27-2013 01:30 PM
Dear sir
Thanx for the response.I am using NI-9215 and cdaq-9172 for obtaining the outputs from a proximity sensor (Bently Nevada 3000 series).I am unable to obtain the proper outputs from sensors. can you devise me some means to obtain the outputs as these type of proximity sensors had completly become obselote. I am sending you small writeup regarding my system
09-27-2013 02:00 PM
What outputs are you getting from the proximitors?
The B-N's we use put out up to -24 volts. A cDAQ-9215 is rated for +/-10V, thus would not be able to measure a value that high. Now if the probes were set close enough, then the DC value of the signal probably could be set to less than 10 volts.
What are the outputs you are getting if you don't use NI equipment, but use a multimeter? Are they what you expect? If not, then you have a hardware problem, and there is no way to fix that unless you contact Bently-Nevada.