The PSM-E20 is a monitoring module manufactured by Emerson that serves as a data processing center in DC power systems. This monitoring module communicates with the charging module, distribution monitoring, insulation instrument, battery instrument and other devices through multiple communication ports to collect the operating data of the power operation power system, and complete the automatic equalizing and charging conversion of the battery pack according to these data.

The main functions of the PSM-E20 monitoring module include:
Automatically records the start time of equalization and floating charge, and continues charging after power-on or reset.
Timing equalization function, users can set the time interval and equalization time.
Equalized charge control after the battery is discharged. When the AC power supply is restored again after the battery is discharged, if the battery current is greater than the set value, the equalized charge is automatically performed.
Multiple battery management functions, such as setting floating charge voltage, temperature compensation, capacity analysis, and more.
Supports automatic and manual control to meet different maintenance requirements.
Troubleshooting capability: When an exception occurs in the system, for example, the bus voltage is abnormal or the battery fuse is disconnected, the monitoring module automatically sets the battery to the floating charge state and opens the current limiting points of all modules.
The alarm function sends alarm signals through the display, panel alarm indicators, buzzers, and relays.
Background communication capability, support RS232/RS485 communication, communication protocols including Modbus, CDT91, DNP3.0, IEC101 or IEC103.
In terms of technical parameters, the PSM-E20 can monitor a variety of analog and switching quantities, such as AC voltage, bus voltage, battery pack voltage, load current, battery current and battery ambient temperature. At the same time, it can also monitor a variety of switch signals such as the on-off state of the branch, the on-off state of the battery fuse, and the alarm state of the insulated relay.