## Detecting downstream devices

A downstream device is one whose data is logged by a remote data recorder, for example:

A Modbus slave device whose output registers are logged by a device with Modbus Mastering capability (see illustration below).

A Modbus device whose outputs are logged by the .

Any of various multiple sources in which the same measurement is being logged on a single device, for example, an RTU that is collecting kWh pulses from multiple sources or a single branch circuit monitor that is collecting current readings on multiple circuits.

A | server | B | Ethernet | C | kW | D | Data Recorder
E | Physical source (Modbus Master) | F | RS-485 | G | Downstream Devices (Modbus Slaves)

automatically detects downstream devices. The component does this by looking for devices (called “physical sources”) that record or host data coming from various downstream devices (for example, an meter that utilizes a Modbus Import module to pass through data originating from a “downstream” Modbus device).

resolves the data from each of these downstream devices to the appropriate measurement (for example, the label “Vll ab” resolves to the measurement “Voltage Phases AB”). For data that cannot be resolved, creates measurements whose names are based on the ION register labels.

uses a logical naming scheme to assign names to the downstream devices. For example, “Modbus.34” is the name assigned to the downstream Modbus device with a slave address “34”.