Ethernet MeterBus Converter

Ethernet MeterBus Converter

The Ethernet MeterBus Converter™ (model: EMC-1) provides the data and communications connection for Morningstar devices, between themselves, with surrounding systems, and with the outside environment through the internet. It’s simple to connect to Morningstar products equipped with an RJ-11 Meterbus port to enable remote monitoring, custom programming, and access to future cloud-based data services.

Protocols and technologies supported by the EMC-1 include:

  • HTTP for LiveView: a simple and straightforward web dashboard for checking system status easily from any device browser
  • SNMP (Simple Network Management Protocol): provides more detailed monitoring of all system data with existing IT management architecture
  • MODBUS Industrial Control: provides high-speed monitoring and control for industrial equipment Compatible Morningstar products include:

    The EMC-1 converts this connection into a fully enabled Ethernet port allowing data transfer to the internet. Once connected, the MeterBus port enables transmission of serial data to the EMC-1 for remote monitoring, configuration, and control, using any type of IP-based network connection. This way, many new, powerful integration options for Morningstar products can be activated and used in remote power systems.

Key features and benefits

  • Adds SNMP to deliver real-time system data
  • Enables Live View to display system status and log data directly from the EMC, in an easy-to-view webpage
  • Adds IP-based MODBUS connectivity for remote
    industrial communication and control
  • Connects to any MeterBus-enabled controller to provide enhanced data and network features
  • Powered via MeterBus port on controller or DC Input for 12, 24 or 48V systems
A. Premium high-frequency CoilCraft surface mount inductors

They’re worth it, because they provide the faster power “tracking” that lets us engineer this much power and control into a compact design.

B. High-frequency design

Combined with premium, “over-spec’d” components, this greatly improves control response which guards against system transients, regulation overshoot and overcurrent/overload conditions

C. Built-in 4500W Transient Voltage Surge Suppression for lightning protection

Nature do your worst–this controller can take it

D. Large diameter, high torque, corrosion resistant terminals

If you’ve ever trashed a lesser terminal during an installation, you’ll appreciate some “overkill” here

E. DirectFET™ MOSFET power devices

Allows the surface-mounting of critical components underneath the main board next to the heat sink, which reduces heat travel distance and keeps the controller even cooler

F. Highly-conductive aluminum heatsink extrusion

As opposed to cast aluminum, which is less effective in passive cooling applications

G. Communications/data port with serial/meter auto detect

“Talks solar” with standard industry language, for system monitoring and cloud connectivity-speaks Modbus, and SNMP (with the EMC-1)

H. Lithium foldback circuit

Lithium batteries are expensive and vulnerable to cold temperatures. When it gets close to freezing, the controller backs-off charging to avoid damaging batteries

I. High-speed ARM processor

All-digital calibration for high accuracy, using the same efficient technology found in advanced mobile device

J. TrakStar™ Technology

Morningstar’s hallmark MPPT technology precisely seeks and locks onto the true maximum power point quickly and accurately, to ensure the highest output possible from a solar array

K. Large format, high-resolution backlit LCD

When you’ve been in the field installing, you appreciated being able to read a crisp, high contrast display on site

L. 5 year warranty

Up to 2 1/2 times longer than some competitors in this class

M. Self-diagnostics

ProStar is smart enough to monitor and analyze system performance, and alert you when you need to know

N. High temperature architecture

Heat is the enemy of all electronics. That’s why Prostar’s critical components are rated to withstand temperatures right up to the boiling point of water (100°C)

O. Lexan polycarbonate UL listed case

Protects the precision electronics inside with an impact strength 30 times greater than the acrylic thermoplastics commonly found on lesser controllers

P. Cooling Fan

Just kidding. We’ve never needed them

Specifications and Certifications

Model EMC-1
DC Input Supply Voltage Range 8-80 Vdc
Maximum Self Consumption 2 Watts
Operating Temperature Range -40 C to +60C
Warranty 5 Years
CE and RoHS Yes
FCC Class B Part 15 Compliant Yes
Manufactured in a Certified ISO 9001 Facility Yes

Operation Manuals

Download the Ethernet MeterBus Converter Manual.


Ethernet MeterBus Converter (EMC-1) - 3 minute video

This 3 minute video provides an overview of Morningstar’s new Ethernet MeterBus Converter (EMC-1). This device enables IP based network and internet connectivity to any Morningstar solar charge controller or inverter that features an existing MeterBus port (RJ-11) including: PWM controllers: TriStar and SunSaver Duo; MPPT controllers: TriStar MPPT, ProStar MPPT, & SunSaver MPPT;  Inverters: SureSine. And future products that feature an existing MeterBus port (RJ-11).

Morningstar Charging Experts featuring ProStar MPPT

This 5 minute video highlights the ProStar MPPT solar charge controller’s circuit board that differentiates it from other brands. In addition to the capacitors, inductors, processors, surge protectors, and other over-spec’d internal components, the quality of the controller’s heat sink and outer casing is also addressed. The video concludes with mention of features and capabilities related to communications, datalogging, lithium battery charging, and high quality and reliability.  

Ethernet MeterBus Converter Webinar

Recorded Webinar

View this recorded webinar to learn about the new Ethernet MeterBus Converter which enables the addition of IP based network and internet connectivity to any Morningstar product that features an existing MeterBus port (RJ-11). 


  • Boating
  • Lighting
  • Oil & Gas
  • Railroad
  • Rural Electrification
  • Residential
  • Security
  • Transportation
  • Traffic

Related Products

  • TriStar MPPT 600V

    600 volt charge controllers with 60 amp charge rating

  • TriStar MPPT

    MPPT charge controllers (150 Voc; 30, 45, & 60 amp versions for 12-48 volt batteries)

  • TriStar


    PWM charge controller (45 & 60 amp versions for 12-48 volt batteries)

  • SunSaver MPPT

    MPPT charge controller (60 Voc; 15 amp rating for 12 & 24 volt batteries)

  • SureSine

    Pure sine wave inverter (300W continuous; 600W peak for 12V batteries)

  • ProStar

    PWM charge controller (15 & 30 amp versions for 12 & 24 volt batteries)

  • ProStar MPPT

    MPPT charge controller (120 Voc; 25 & 40 amp versions for 12 & 24 volt batteries)

  • SunSaver Duo

    PWM two battery controller for RV's, & boats (25 amp rating for 12 volt batteries)


It’s a recommended best practice to install your product’s latest firmware to ensure access to all up-to-date features, accessory compatibilities, and code modifications. Follow instructions in the EMC-1 Firmware pdf to locate the most up-to-date firmware. Then, watch this video for instructions on how to update EMC-1 firmware.

System Diagram

The diagram above shows how connections are made with the RJ-11 cord between the Morningstar product on the right and the EMC-1 in the middle.  The EMC-1 is connected to an Ethernet gateway which is typically a router or switch that you see on the left.

Select Morningstar products that previously could not connect to an IP network or internet can connect to the EMC-1 to enable a view of many useful system metrics via web browser such as:

  • Battery voltage
  • PV current
  • Load current
  • Faults or errors within the system

This information will appear live in real time, so you will see data changing without having to refresh your browser.  Furthermore, you can use our free MSView software with the EMC-1 so you can change your battery charging settings, low voltage disconnect settings, and lighting settings.  Every product in MSView has its own setup wizard for adjusting the custom settings. To make it easier to use MSView setup wizards, we’ve created a webpage that lets you download custom settings configuration files.



    Off-Grid Diagram with AC Load

The schematic diagram above, illustrates how the ProStar MPPT regulates power to batteries and an alternating current (AC) load in an off-grid system.  This diagram is very similar to the DC load diagram above it except an inverter has been added.

  1. Sunlight contacts the solar modules, which convert solar into DC electrical power that it delivers to a charge controller.
  2. The charge controller regulates the amperage and voltage that is delivered to the battery system so the batteries maintain their state of charge without getting overcharged.
  3. Batteries deliver power to the inverter which converts DC to AC power that it delivers to the load.  Notice that  the inverter is connected to the battery, not the controller’s load terminals, like we did in the DC load example.  That’s because the inverter can have a high energy surge upon start up, and this high current surge might be higher than the rated capacity of the charge controller, whereas the batteries will be able to meet the high energy surge requirement.