Frequency counter help!

Hi all.
I'm really in need for help. I have a Wago PLC frequency counter module. I have it wired to the Magnetic pickup module of the engine. I have a problem reading the manual, and I'm embarrassed to say I can't really understand the manual. I need to find out to which terminals should I wire my MPU (2 wire, + and -).
Can someone help me please??

regards
Sherine T.

I do not understand your situation entirely BUT I may be able to offer some help. In the US a DC device usually has 2 leads that are red and black, red is positive and black is negative. From experience, not actual knowledge of standards, European DC devices use Brown for positive and Blue for negative.

IF you can post a link the the manuals for your specific devices someone may be able to assist in where to put what wire.

I have a Wago PLC frequency counter module. I have it wired to the Magnetic pickup module of the engine.

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This sounds like a device for measuring RPM? The unit then can be configured to give an analogue OP, and/or digital OP based on RPM.
I had an IFM module, that did the same thing.

The 2 wires will go to this unit, you just need to find the sensor terminals.

As Ron said, if you can post any information that you have, either from the manual, or what is printed on the side of the unit, we should be able to help you.


Do Wago do a PLC?

Yes they do

scottmurphy:
Yes Wago does PLCs.

Ron:
I understand that a MPU has a positive lead and a negatie lead. It's just this module is giving me a little bit of a problem. It has an Up/Down counting function as well as a clock function. whatever it is, I have the manual attached here. Do help me out with it. I went on site to check it out, and the speed is not showing on the tachometer, even though the module is picking up the speed from the MPU. when I removed the negative lead, the tachometer sort of "spiked up" a little. I had it wired to the 'Clk' (positive lead) and the '0V' (negative lead).

Thanks!!

regards
Sherine T.

Yes Wago does PLCs

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You learn something new every day.


That link did not seem to work either.

That link did not seem to work either.

Click to expand...

Yes...after I uploaded it there seems to be a problem. Let's try the actual website for a change.

I really have to brush up my interpretation of the language better.

regards
Sherine T.

jolio ST said:

Yes...after I uploaded it there seems to be a problem. Let's try the actual website for a change.

I really have to brush up my interpretation of the language better.

regards
Sherine T.

Click to expand...

Here in our plant we use Wago as Bus Coupler Profibus DP/FMS to communicate the Siemens S7-300 PLC. It`s very nice cause we eliminate a lot of I/O to be use. Same as I/O module it will communicate via the address you put in different Bus Coupler of Wago.

This manual is confusing!
Gate LED should be off. Clock LED is pulsing if your pickup is working.
You can configure this module to use OUTPUT 1 (DO1) or OUTPUT 2 (DO2).
If it is configured for OUTPUT 1, then the DO1 LED will be on.
The configuration is set with the 'Control Byte'. It is described on page 34.

Connect '-' to 0V (terminal 3 or 7) and '+' to DO 1 (terminal 4) or DO 2 (terminal 8).
Gate (terminal 1) should have no connection, or connect to 0V. If you connect Gate to +24V, you will disable the output.

Sorry for not responding sooner.

The manual would be confusing but you did state it was a frequency counter.

The module for a frequency counter is 750-004/000-003, page 27. If I have read this correctly your INPUT should be on the CLOCK connection. The GATE connection should be 0 (zero) volts, to disable this process you would apply 24v to the GATE.

One lead of the magnetic pickup will be supplied by the 24v supply, the other lead goes to the CLOCK input UNLESS it is a 3 wire unit which is not common. Can you show a link to the MPU device? Usually you will connect what is considered the + of the MPU to the power supply and the - to the CLOCK input.

D01 and DO2 are digital outputs.

The module should also have 24v power supplied to it.

Hope this helps Sherine.

BTW forget about the MPU having a positive and negative lead, technically it does not.

Sorry, I thought MPU was Microprocessor, but it's Magnetic Pickup Unit.
Ron, I believe you found the problem - The MPU needs to be powered.
The Clock input is looking for a 24 volt signal to drive an optoisolator.
If it's working, you will see the 'Clock' LED pulsing.
If the MPU has a + and -, then connect + to 24DC, and the - to Clock.

So sorry for the late reply

Hi guys. I am so sorry for such a late reply. I was away to the site for a while and then I went off to Taiwan for another site comissioning. A real busy schedule packed with frequent travelling. And I have come to a shocking discovery when I went on site with the frequency problem. I found that module was actually a wrong model. The manual, once I read it for another few times, did state that 750-404/000-003 is the frequency counter. What is in place currently was a 750-404/0: an up/down counter. So natually it will not work when connected to the MPU. So I had a report to the man-in-charge to have the module changed. It's gonna be big! There are a total of 18 panels, and not one is a frequency counter!
I do have the image of the autocad. Well, I'm used to calling it a positive and negative lead, since it's wired to a positive and common lead in some other devices.


Thank you so very much, Ron, keithkyll and Maj. Toxido for your help!

A mag pick up does not need a power supply to it. It generates it's own voltage up to about 5 volts. If you get 5 volts you are doing well - I normally see up to about 3+ volts.

These things are normally used on generators (flywheel) to indicate speed to a generator controller, RPM indicator, crank/under/over speed relay etc. I see them nearly every day.

The biggest problem is the MIL type plug and soldered connection. They invariably break off the wire at the solder joint if the MAG pick up is not mounted properly and/or the cable is held rigid due to vibration. The attached device then goes berserk.

Yes Bob. I'm in the power system company, working on the control side of projects.
I'm sad to say, I have very limited knowledge on the equipments mounted on the whole generator, and only get to work on what ever stuff them engine peeps want to throw into the control side, or what operation they require to be done. I have no idea what make of the MPU is mounted on the engine, but I have engineers telling me that some pickup units are so badly made, they don't last long on the generator. How true is that?

regards
Sherine T.

Very true Sherine. I will only use Woodward or equal quality MPUs.

A major part of my business is diesel generator systems for emergency power and prime power. I have worked with Woodward controllers (OK), Deep Sea controllers (OK for very simple systems), Crompton controllers (a bit surprisng actually are quite good), SDMO control system (don't ask), Si-TEC controllers (the best in my opinion), Regulatore Europa, Babcock and Wilcox controllers, Wilson Ireland sets (hate 'em), Caterpillar sets, Perkins sets, Dorman sets, Deutz sets, MTU sets, Detroit sets, Paxman sets, Watzilla sets, MAN sets, Cummins sets, English Electric sets, Allan sets, KATO, Leroy Somer, AVK, Newage, Stamford, McColl, and many other alternators, engines, controllers and a whole pile of PLCs.

At the end of the day you very quickly get to a point where you know what you like to work with and, more importantly, when to run the other way.

Then there are SCADA systems etc. Citect is still my favourite by a mile quite frankly.

When programmong, the most important thing to me is the programming software. Can lose a bundle there. I like Omron, as most are aware, and Citect. When doing my tags for the PLC and for Citect, I work in Excel. Modify, copy and paste into Omron CX-Programmer and at the same time use Excel for the tag dbf file in Citect. Just have to set up the column width correctly. At the same time Word is open and a graphics manipulation package as well as on the internet to find graphics for my projects. Very seriously considering buying the lates Dell 24" LCD screen (or two). Rave reviews and quite cheap. Better than monitors at twice the price apparently.

I do my own designs, quite often build the control panels, software, commissionig, SCADA etc. Then come the hassles over manuals.

When designing a system, I basically do it the way I want so that the software is easy. A couple of extra inputs can make the world of difference. Good to start at the beginning and finish at the end.

Good luck and regards
Bob