SAJ Inverter R5_V1
Monitors a single-phase SAJ solar inverter via Modbus RTU
This template connects to a SAJ R5 single-phase solar inverter via Modbus RTU at 2400 baud. It reads PV string voltages, currents and power for up to three strings, AC output parameters, energy totals, inverter temperature, fault messages and insulation resistance values.
- Protocol
- Modbus RTU
- Connection
- RS485, 2400 baud
- Registers
- 47, read only
- Brand
- SAJ
- Key readings
- PV1 to PV3 voltage, current, power · AC L1 to L3 voltage, current, power · Total and daily energy · Inverter temperature · Fault message and error count · Insulation resistance ISO1 to ISO4
- Compatible models
- SAJ R5
- Last updated
Registers (47)
47 read, 0 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| 03-256-MPVMode | Read | ||||
| 03-257-FaultMSG | Read | ||||
| 03-263-PV1Volt | V | Read | |||
| 03-264-PV1Curr | A | Read | |||
| 03-266-PV2Volt | V | Read | |||
| 03-265-PV1Power | W | Read | |||
| 03-267-PV2Curr | A | Read | |||
| 03-270-PV3Curr | A | Read | |||
| 03-268-PV2Power | W | Read | |||
| 03-269-PV3Volt | V | Read | |||
| 03-271-PV3Power | W | Read | |||
| 03-272-BusVolt | V | Read | |||
| 03-273-InvTempC | °C | Read | |||
| 03-274-GFCI | mA | Read | |||
| 03-275-Power | W | Read | |||
| 03-276-QPower | Var | Read | |||
| 03-277-PF | Read | ||||
| 03-278-L1Volt | V | Read | |||
| 03-279-L1Curr | A | Read | |||
| 03-282-L1Power | W | Read | |||
| 03-283-L1PF | Read | ||||
| 03-280-L1Freq | Hz | Read | |||
| 03-281-L1DCI | mA | Read | |||
| 03-284-L2Volt | V | Read | |||
| 03-285-L2Curr | A | Read | |||
| 03-286-L2Freq | Hz | Read | |||
| 03-287-L2DCI | mA | Read | |||
| 03-288-L2Power | W | Read | |||
| 03-289-L2PF | Read | ||||
| 03-296-ISO1 | kΩ | Read | |||
| 03-290-L3Volt | V | Read | |||
| 03-291-L3Curr | A | Read | |||
| 03-292-L3Freq | Hz | Read | |||
| 03-293-L3DCI | mA | Read | |||
| 03-294-L3Power | W | Read | |||
| 03-295-L3PF | Read | ||||
| 03-297-ISO2 | kΩ | Read | |||
| 03-298-ISO3 | kΩ | Read | |||
| 03-299-ISO4 | kΩ | Read | |||
| 03-300-Today Energy | kWh | Read | |||
| 03-301-Month Energy | kWh | Read | |||
| 03-303-Year Energy | kWh | Read | |||
| 03-305-Total Energy | kWh | Read | |||
| 03-307-Today Hour | H | Read | |||
| 03-308-Total Hour | H | Read | |||
| 03-310-Error Count | Read | ||||
| 03-311-TIME | <v.u> | Read |
Loading registers…
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If a device is not in the library yet, we build the template for free as soon as we have the register data.
Use cases
- Monitor PV string voltages and currents on a live dashboard to detect underperforming strings.
- Track daily and total energy production for yield reporting to end customers.
- Create an alert when inverter temperature exceeds a safe threshold for more than 5 minutes.
- Log insulation resistance values over time to detect gradual ground fault development.
- Review fault messages and error counts remotely to reduce unnecessary site visits.
- Compare AC output across L1 to L3 registers to verify correct inverter behavior.
Installation
Connect the ModbusCloud Gateway to the SAJ R5 RS-485 terminals using a twisted pair cable with correct A and B polarity.
Set the serial port on the gateway to 2400 baud, 8 data bits, 1 stop bit, no parity to match the SAJ R5 default settings.
Configure a unique Modbus slave address on the SAJ R5 via its front panel or configuration tool, and note the address for the next step.
Import the SAJ Inverter R5_V1 template in the ModbusCloud platform and assign the correct slave address.
Verify that live data appears on the ModbusCloud dashboard by checking PV voltage and AC power readings against the inverter display.
Things to watch for
Why am I not getting any response from the SAJ R5 inverter?
Check that the baud rate on the gateway is set to 2400. The SAJ R5 uses a lower baud rate than most inverters. Also verify RS-485 A/B wiring polarity and confirm the correct slave address.
Why do energy registers show incorrect or very large values?
Monthly, yearly and total energy values are stored as uint32 across two consecutive Modbus registers. Make sure the gateway is reading both registers and combining them in the correct byte order.
The inverter is single-phase, so why does the template include L1, L2 and L3 registers?
The SAJ R5 register map defines AC output registers for L1 through L3 even though the inverter is single-phase. L2 and L3 will typically read zero. The template maps all three for completeness.
Can I control or configure the inverter through this template?
No. This template is read-only. It monitors PV input, AC output, energy totals and diagnostics but does not include any writable registers.
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