Digital numeric input device with ethernet

PLCDontUQuitOnMe · Jun 1, 2023

I have an application that needs a simple way for an operator to input an integer value and send it to a PLC. An HMI is overkill, but I am thinking of all of the digital counter modules and thumbwheels I have seen mounted to the front of panels over the years. Is there an ethernet version of these that allow for numeric input that can communicate that integer back to the PLC over ethernet? Number would be small, 0-250.

I have looked at a few different manufacturers websites and can't find anything.

Puddle · Jun 1, 2023

PLCDontUQuitOnMe said:
An HMI is overkill

A basic 4" HMI is nearly always the most cost effective solution, even though it seems like a huge waste.

The most simple solution may be a rotary pot and a 7-segment readout like a Red Lion CUB5, but then you need to either use remote IO or serial coms instead of ethernet to communicate, which would probably cost more than an HMI.

drbitboy · Jun 1, 2023

thumbwheel switch, twelve bits (4 per digit), to a remote i/o device that does some kind of fieldbus (Modbus?).

but by the time you put that together you may as well have created a minimal HMI.

do you have any analog inputs on the PLC? 8 bits detecting a knob rotational position (potentiometer/voltage divider?) will cover 0-255, with feedback and a button when the value is at the target? again, probably easier to do an HMI.

drbitboy · Jun 1, 2023

a thumbwheel plus this? I agree with @Puddle. Small HMI is cheaper, better, faster.

If you were making a million of these for the next Kia Soul model year, then a few hundred k$ in engineering a bespoke solution would make sense, but for a one-off for your local plant, you also have to consider your time.

JeremyM · Jun 1, 2023

PLCDontUQuitOnMe said:
I have an application that needs a simple way for an operator to input an integer value and send it to a PLC. An HMI is overkill, but I am thinking of all of the digital counter modules and thumbwheels I have seen mounted to the front of panels over the years. Is there an ethernet version of these that allow for numeric input that can communicate that integer back to the PLC over ethernet? Number would be small, 0-250.

I have looked at a few different manufacturers websites and can't find anything.

If the PLC is Modbus-capable, one could use their cell phone and an app.

PLCDontUQuitOnMe · Jun 1, 2023

Thanks for the ideas. I am going to check if I have 12 inputs available and if so go with 3 thumbwheel switches. Failing that I will look at a small&cheap HMI solution. I looked at some of the 4" AB panelview options and wow they are not cheap right now even in that small size format.

JordanCClark · Jun 1, 2023

A 4.3" Maple Sytems (Weintek) is $299US

A quick look at a 3-digit thumbwheel from Digikey showed $135.75US

bob1371 · Jun 1, 2023

HMI might be a little more but I think still best solution.

https://www.automationdirect.com/adc/shopping/catalog/hmi_(human_machine_interface)/graphical_hmi_devices/hmi_panels/cm5-t4w

plvlce · Jun 1, 2023

PLCDontUQuitOnMe said:
I looked at some of the 4" AB panelview options

I think that right there explains why they're so expensive...

C-more or Maple would be my suggestions as well for something this simple.

joseph_e2 · Jun 1, 2023

Another vote for a small HMI. I know you only need to enter one number, but just wait. It won't be long before "they" want more...

drbitboy · Jun 2, 2023

PLCDontUQuitOnMe said:
Thanks for the ideas. I am going to check if I have 12 inputs available and if so go with 3 thumbwheel switches.

Note that you really only need 8 bits, but that would require an input device, other than three thumbwheel switches, and which may not even exist, unless either the operators are fluent in hexadecimal or you give them an 8-bit decimal => hex conversion table. LOL.

drbitboy · Jun 2, 2023

https://electronics.stackexchange.com/questions/366871/bcd-to-binary-decodersolved

https://pastebin.com/XEfAh8AR

Digital numeric input device with ethernet

PLCDontUQuitOnMe

Member

Puddle

Member

drbitboy

Lifetime Supporting Member

drbitboy

Lifetime Supporting Member

JeremyM

Lifetime Supporting Member

PLCDontUQuitOnMe

Member

JordanCClark

Lifetime Supporting Member

bob1371

Lifetime Supporting Member

plvlce

Lifetime Supporting Member

joseph_e2

Member

drbitboy

Lifetime Supporting Member

drbitboy

Lifetime Supporting Member

Similar Topics