encoder to device with 4-20ma out

[irondesk40]

have a question. I have about 18 machines that involve feeding fabric, glue, etc. and there is a infeed table that I will build that will have a nip roller to feed fabric into what I will refer to as the master machine. The infeed table I have been told will always run a little faster than the master to develop a accumulation of slack material. The master machine I have not seen yet so do not know what type of controls are in it. The only thing I know is that the manufacturer may not be able to supply me a analog sensor to represent the actual speed it is running. I can mount a encoder on a roller that will turn as the fabric feeds across and connect it to a allen Bradley micrologix plc and detect the speed it is running and then use a analog output to a emerson drive that I will be using to control the nip motors. When you multiply this by 18 its a pretty good amount of money. Is there a device such as a redlion, or omega or something that the output of the encoder could be connected to and then give a analog output such as 4-20ma to represent the masters 0-10 YPM it may be running? I have looked at some redlion counters etc. and wondering if anyone has used something like what I have described to detect the speed of rollers, etc. and give a analog output. Just think it would be simpler than possibly using a plc and more cost effective.
Thanks

 

[TimWilborne]

I know you asked if a Red Lion or something would do it, but the Micrologix's high speed counter can accept the encoder input and output the 0-10VDC. Any reason you don't just use it?

 

[irondesk40]

Thanks TW, I have quite a few machines that I am using a micrologix plc to do that but was thinking that maybe RedLion or Omega or some other vendor made a device that would take the encoder inputs and output a analog output and be cheaper than the plc, panel to put it in etc...
I was looking into something like a panel mount device similar to a temperature controller that could be scaled from the front to give the output to represent the speed that I could then just connect directly into the analog input of a Emerson drive that will also have a inclination sensor that will be trimming the drive plus or minus a percentage. Do not know what type of controls the machine will have only know its 18 of them and with the back load of projects just looking for a quicker way that would also be simpler for techs in the branch plants.

 

[TimWilborne]

I've never used it but looks like Red Lion does have a device for that.
http://www.redlion.net/Products/ProcessControl/SignalConditioning/FrequencyInputs/IFMA.html

 

[irondesk40]

Thanks, I searched them today but did not see that one. Will download info and call rep tomorrow and do a price comparison.

 

[TimWilborne]

Also for price comparison you might think about a DL05 with an analog card.