Load cells to PLC solution

[testsubject]

If I remember correctly, I think the Survivor has "RattleTrap" tech built in. This is a neat feature that will sample the harmonic vibration and cancel it out so that the display reads the true weight without vibration causing any problems. Most of the high end indicators from Rice Lake has it. (I have used it on the IQ-710/800/810)

Another thing to take into account when thinking about analog in/out is the resolution of the plc analog card. For example, If you want to measure 500.0 lb full scale in .1 lb increments, you cannot with an analog input card that is only 12 bit. It is only capable of displaying 0-4095. Something to think about.

Bob

 

[curlyandshemp]

I don't like to depend on outside sources for this. I keep calibration weights, so any technician can verify calibration and calibrate at any time. It's easy to program an HMI to allow this so even some operators are capable of handling it. I do agree that for precision, a dedicated controller interfaced to the PLC would be superior to a roll yer own approach. Next time I have to do a new one, I'll definitely investigate one of the backplane type modules.

Well,

next weekend I am commissioning a batching system in Spokane that has 5 x 10,000lb hoppers. I am sure glad that the customer has a scale company lined up to calibrate the Hardy Instrument scales that are connected via RIO to the Contrologix I am commissioning. I would hate to see the surcharge the airline would charge me to bring 1000lbs of test weights with me.


Ian Phillips
flomation engineering

 

[Alex Pel]

“timeout timer” to halt the batching process? It looks like only thing I can do for now. Ok let’s try to play. From “Survivor” I am receiving 6 discreet signals:

1,2,3,4,5 – “augers start/stop”, 6 – “At weight” .

Empty hopper is a common case, especially for low consumption materials like color additive. Instead of silo that components are loading from a floor bin. Pipe stuck in there and emptiness appeared around. So, it is a common practice then pump is sucking nothing. It might take time from couple minutes to half an hour regardless of flashing alarm. Our operators are really busy and I understand that better to re-stick pipe when coming by. Negative - “timeout timer” will extend pump lifetime but not operator’s one.

Loosing 10 kg of materials or blown fuses even blown pump doesn’t look like a big issue. QA might be a problem, but #1 is downtime. If coating line stopped it will take about half an hour to start it again and about 200 kg of materials plus meters of web will be lost. Basically maintenance have 5 to 10 minutes to restart “Survivor” after double batching, but about 1 of 10 times we could not prevent line of stopping. If I have an access to the “Survivor” program I could find out a cause. It may be that mentioned timeout or may be output relay. Honestly I don’t want to learn that “Survivor” book, but looks like I have no choice. It might be some incorrect parameter or just replace the board.

Thank you anyway; at list I learnt a good solution with Hardy. May be one day we will kick that “Survivor” out.