EKM Omnimeters communicate via RS-485 with the EKM Push3 gateway or the EKM Blink USB Converter. Regardless of the communication device, the wiring connections are the same. RS-485 communication is done with 2-wire connections that connect A and B ports on the meter(s) to A and B ports on the communication device.
Connecting a single meter to one communication device:
- To connect a single meter you simply wire the A port on the meter to the A port on the communication device.
- Similarly, the wire would go from B port on the meter to the B port on the communication device.
Connecting multiple meters in a daisy chain to one communication device:
- To connect multiple meters you simply wire hop from A port to A port on all of the meters in series, until you finally make it to the A port on the communication device.
- Similarly, the wire would go from B port to B port on all of the meters in series, until you finally make it to the B port on the communication device.
- This diagrammatic video shows how this is done:
If your power wires are in conduit, that will make a huge difference when it comes to reducing interference with the RS-485 communication wires. Also, the closer the communication wires are to the power wires, and the more length that is parallel, the higher the chances for problems, so keep parallel runs of power and RS-485 wires as far apart as is practical.
- Keep the intersections of communication wires with power wires as close to 90 degrees as possible.
- Use shielded CAT5, CAT5e, or CAT6 cable when you can. These cable have 4 twisted pairs of wires in them. Each RS-485 connection will use one of the twisted pairs. Shielded cable protects the communications in electrically noisy environments.
- When making wire connections it is a good idea to apply dielectric grease to the connection points. Because CAT5/6 wires are so small the connections can easily become corroded and unreliable over time. Adding the dielectric grease prevents corrosion and will ensure that the connections last as long as possible. This is a particularly good practice in marine or humid environments.
- Only connect a single communication device at a time. If you're trying to read the meter(s) with multiple communication devices at a time the communications will become garbled and you will receive bad data.
- Two or more 485Bee Zigbee radios can be used to wirelessly bridge the communication between the meter(s) and the communication device. More on this here.
- The wired connections between the meter(s) and the communication device can be up to 4000 feet long.