On 10/29/2014 11:24 AM, wrote:
On Wed, 29 Oct 2014 11:06:40 -0700, Todd wrote:

Hi All,

Have a farmer for a customer with a large water
tank for watering his fields. He would like some
telemetry as to its state: full, half full, etc..
(Currently he uses the "There She Blows!" method
to see when the tank is full.)

Anyone have any suggestions? Be nice if it worked
over Modbus/TCP.

Many thanks,
-T

How far away?

He is within Wireless range

Why would he need the complication of TCP.

It supports Modbus with supports his Red Lion controller
http://new.redlion.net/hmi-operator-panels/g3-series

He wants to show tank level next to his pump controls.
Eventually he wants to have the pump automatically turn
off through the Red Lion controller.

I am thinking 2 wires, a variable resistor at the tank and a gauge
that responds to it, similar to the gas gauge in a car.
That would not require any power at the tank at all.

Like a huge toilet float?