title: PLC modbus datalogger that can push data to a web server
body: <p>We are looking for a data logger to connect to a PLC through Modbus TCP or RTU.  I have found several of these on the market, but I need the ability to post the data back to a web server.  Basically we have a website that uses a graph to show the current values from the PLC over time and this data shouldn’t be more than a few seconds old.  We have used a raspberry pi, but we are looking for alternatives for a more industrial environment. </p>
  
  <p>Critical features
  1.  If the connection is lost, then the data that has been logged since the last connection should be sent up.
  2.  A backup of the logged data should be stored on the device
  3.  Use some type of frequent update mechanism to send data to the server like a html post. </p>
  
  <p>I have only found one device and I wonder if Im using the wrong search terms/lingo or if COT devices do not exist with these features.</p>