Mobile Telemetry for Remote Power Metering

Remote Metering Products

Using Mobile Telemetry for Remote Power Metering in large facility.

Defining the Problem:

This applies at a large military complex.  Electrical usage is sent from Substations to the Electric Utility only. The Public Works division onsite would like to establish a data collection system of the power usage for energy auditing and optimising operations. Remote Power Metering is the perfect solution. Due to obstructions and installation restrictions, the telemetry system would operate over a 3G/4G LTE mobile network using Digi WR21 Mobile Routers.

System Requirements:

Substation Electric Power Meters’ outputs are sent to the Utility.  The data collection system sends via Electrical Isolation Relays. A relay output, 1 pulse = 1 kWh, is connected to an input channel on the 989EN-4016. The current totalised count is converted to Modbus TCP/IP and connected to the Ethernet port on the Mobile Router.

Acromag 989EN-4016 16 DIO / Up to 8 Counters

Remote Power Metering Products EN989

Implementing the Remote Metering Solution:

  1. Firstly, set up a Private APN with a Mobile Carrier to reserve internally customer supplied IP Addresses
  2. Secondly, configure the Mobile Router IP Address using a reserved IP Address. For example,
  3. Thirdly, in the Mobile Router, configure the Ethernet Port Forward with the IP Address of the device connected to its Ethernet port.  Either the 989EN-4016 in the field or the Server IP Address in the Control Room.  The Server software would send a Modbus TCP/IP message to the IP Address of the Mobile Router that would forward it to the 989EN-4016
  4. Fourthly, for multiple field locations, the Mobile Router at each site can have a unique IP Address (,, etc).  But every Acromag 989EN-4016 connected to it can have the same IP Address (  This standardises the set up for unified configuration.
  5. Therefore, for the data collection, the Server can request the totalised count from the 989EN-4016 at any time.  To do this, program the Server application software to Open and Close a Modbus socket with each message exchange.

Finally, this application note was provided by our supplier Acromag.  For more information, contact us.