Simple numeric input to PLC

[russrmartin]

Anyone have a cheap, simple solution to enter a desired batch size into a PLC? I had planned to use a selector switch to increment or decrement batch size and display their selected value on a small numerical display. They are saying they'd like to enter the value like they would on a full HMI but are not willing to introduce something along the lines of a touchscreen HMI.

I'm thinking something that can output 0-10 for a 0-9999 value would suffice but not sure such a thing exists.

Ideas welcome!

 

[Archie]

What model PLC is it for?

 

[russrmartin]

It likely will be a Micrologix. I'd like to not tie up a comms port if possible.

 

[LadderLogic]

A bank of thumbwheel switches maybe?

 

[WillM]

I've never used one personally but AB's Panelview Component looks perfect for this. This one specifically will be very cheap and should go hand in hand with a Micrologix...


C200 - 2711C K2M

If you go with a Micrologix 1100 you could run this over RS232 and have Ethernet comms free.

 

[Firejo]

If you go with a Micrologix 1100 you could run this over RS232 and have Ethernet comms free.

It’s worth noting that assuming you connect to the MicroLogix 1100's channel 1 port via a switch, it can be used for communications to an HMI and still be available of other connections. That's why Ethernet is such a good fit for PLC's.

Having said that I don’t believe the PV Component MHI support Ethernet so you would need to use the channel 0 port via DF1 (RS232 or RS485), or DH-485. Either way you’ll be tying up the port.

 

[Archie]

It would tie up a port, but what about a barcode reader and a printed sheet of barcodes for the batch sizes?

 

[RET]

Ta-Da!!! (Waves the magic wand)

http://www.walkerindustrial.com/v/vspfiles/pdf/datasheet/RedLion/redliontsw.pdf

 

[RET]

Or you could use a 2-bit grey code rotary switch like this, and write some code to detect rotation, to count up or down.

http://www.potentiometers.com/pdf/388E.pdf

 

[RET]

Or maybe just use one contact of a rotary switch to pulse an input to increment, and then two buttons on two separate inputs the operator has to push to indicate the direction, up or down. So to go up, he would push and hold the up button, then turn the dial (either direction), and so forth with the down button.

 

[Archie]

Ta-Da!!! (Waves the magic wand)

http://www.walkerindustrial.com/v/vspfiles/pdf/datasheet/RedLion/redliontsw.pdf

4 digits at full parallel would require 16 inputs

With it multiplexed, you would need 4 inputs and 4 outputs, but then a bit of a hairy program to decode.

The ML1100 only has 10 digital inputs, so you would need an expansion card for full parallel. At that point you are probably not far from the price of a small HMI screen.

 

[OkiePC]

How about a G304K2? I know it is a touchscreen but for under $400 and the cost of a cat 5 cable and (optionally) a switch... That is, in my opinion, the most reliable and effective way to give them what they want, not to mention the other features and future expansion you can gain.

 

[willxfmr]

like they would on a full HMI but are not willing to introduce something along the lines of a touchscreen HMI.

We want HMI functionality, but don't want to pay for an HMI. You gotta love it....

 

[baldone]

http://www.fractioni.com/inc/sdetail/218/35863

$283 with free shipping for a 7 inch color Weintek. Software is free.

http://www.fractioni.com/inc/sdetail/218/35863

I have bought both 7 inch and 10 inch from here and had good luck.

 

[(8{)} ( .)]

If you're looking for very low cost you should look at a simple, Modbus enabled thermostat. Something like this:

www.datanab.com/zc/index.php?main_p...ducts_id=122&gclid=CN2y8PPxmsYCFVTMtAodBtIDaA

We had a project years ago where everything was driven by cost, cost, cost and we found something similar for around 50 bux. It's still working. I don't remember (or have access to right now) the product but, again, something similar to the link above will do. Just look around for exactly what you need.

Good luck,

Yosi