All five registers return zero even during daylight. Why?

Confirm the inverter is in normal operating mode and not in standby or night mode. The 3000-range input registers are only populated when the inverter is actively converting PV power. Also verify the slave address on the inverter LCD matches the unit ID in your portal configuration.

I get CRC errors or timeout responses on every poll. What is wrong?

Check RS485 wiring polarity first: Growatt does not always follow the industry-standard A/B labelling, so swap the two data wires if errors persist. Ensure no other device on the same RS485 bus shares the same slave address, and confirm the baud rate is set to 9600 on both the inverter and the Gateway.

Power readings look ten times too high compared to the inverter display.

The raw uint32 values in registers 3005, 3009, 3013, 3017, and 3053 carry a scale factor of 0.1. If your portal integration does not apply this scaling, all readings will be one order of magnitude too large. Check that the template scaling is applied before display.

power_c and power_d always read zero even though strings are connected.

Not all TL-XH models have four active MPP trackers. Single or dual-tracker variants leave the higher-numbered string registers unpopulated. Verify your specific model's number of MPPT inputs in the datasheet; zero readings on unused string registers are expected behaviour.

Free Modbus template: Growatt TL-X(H) Hybrid Inverter (pv)

The Growatt TL-X(H) is a hybrid PV inverter in the MIN series, designed for residential and small-commercial solar installations with optional battery storage. This template connects over Modbus RTU via the inverter's RS485 port and reads per-string PV power across four inputs (power_a through power_d) and the cumulative total PV energy counter (energy). All five registers are input registers read with function code 4 from the 3000-range address space. Having all string power values in one portal view lets installers detect under-performing strings and track lifetime yield without proprietary cloud access.

Name	Address	Function	Type	Unit	Access
power_a Instantaneous PV string 1 input power, raw value scaled by 0.1.	3005	FC04	uint32	W	R
power_b Instantaneous PV string 2 input power, raw value scaled by 0.1.	3009	FC04	uint32	W	R
power_c Instantaneous PV string 3 input power, raw value scaled by 0.1.	3013	FC04	uint32	W	R
power_d Instantaneous PV string 4 input power, raw value scaled by 0.1.	3017	FC04	uint32	W	R
energy Cumulative total PV energy generated, raw value scaled by 0.1.	3053	FC04	uint32	Wh	R