
Modbus TCP
SunSpec Model 501 — Solar Module
SunSpec
Overview
SunSpec Model 501 is the Solar Module information model defined by the SunSpec Alliance, used by PV optimizers, module-level power electronics, and compatible inverters to expose per-module data over Modbus TCP. This template reads output-side measurements (current, voltage, instantaneous power, and cumulative energy via outa, outv, outw, and outwh), input-side string values (ina, inv, inw, inwh), module temperature (tmp), a seconds-based timestamp (tms), and standard event and status registers. Three write registers (ctl, ctlvend, ctlval) allow module-level control commands. ModbusCloud Gateway connects to any SunSpec Model 501 compliant device and surfaces all data in your portal with no custom coding.
Use cases
- Monitor per-module output power in real time to identify underperforming panels across a multi-string array.
- Track cumulative input and output energy (inwh vs outwh) to calculate optimizer conversion efficiency over time.
- Alert on active event bitfield flags (evt) to detect module faults before they reduce total site yield.




