PM2120
The EasyLogic PM2120 is used as a submeter in building management and HVAC applications. With 96×96 mm panel mounting, a backlit LCD display and RS485 Modbus RTU communication, integration into a BMS is simple.
| Voltage (Phase-Neutral) | Vln L1/L2/L3 + average — 0.1 V resolution |
| Voltage (Line-Line) | Vll L12/L23/L31 + average |
| Current | I L1/L2/L3/Neutral + average — 0.01 A resolution |
| Power | kW / kVAr / kVA — phase + total |
| Power Factor | PF — −1.000…+1.000 |
| THD | Voltage + Current THD — L1/L2/L3 |
| Energy | kWh import · kWh export · kVArh · kVAh |
| Accuracy | Class 0.5S (IEC 62053-22) |
| Communication | RS485 Modbus RTU |
| Data Type | FLOAT32 (2 reg, Big-Endian) |
| Mounting | 96×96 mm panel front |
| Display | Backlit LCD |
| Power Supply | 100–277 V AC/DC |
Integration with Argus EMS
The PM2120 connects to Argus EMS over Modbus RTU over an RS-485 serial line, and because a ready register template ships with the platform you do not have to work out a point map on site. The field agent polls the device every 60 seconds by default, writes the reading into a local queue first and then forwards it to the server over MQTT/TLS; nothing is deleted before the server acknowledges it. Hourly and daily summaries are derived from these raw readings, and the consumption and cost screens are fed from the same series.
| Protocol | Modbus RTU over an RS-485 serial line |
| Connection path | The RS-485 line lands on a Modbus TCP gateway or on the field PC serial port |
| Default polling period | 60 seconds (field agent) |
| Points in the ready template | 28 registers |
| Consumption calculation | Difference of the kWh import index over the period (MAX − MIN) |
| Data assurance | Local queue plus server acknowledgement; nothing is deleted before it is confirmed |
When Is This Model the Right Choice?
It is enough to meter a single panel outgoer or tenant feeder: current, voltage and the kWh index are read, which is the baseline monthly billing and sub-metering need. If harmonic analysis, waveform capture or event logging is expected, a higher series should be chosen.
The device has a serial output, so it joins the existing RS-485 line instead of requiring a dedicated Ethernet run into the panel. The more devices share one line, the longer a polling round takes, which is why the field agent reads each line sequentially and waits 60 ms between devices by default. A slave ID collision and a missing line termination are the two most common commissioning mistakes.