Types of Protocols
Modbus RTU Basics
CRC Details
Serial Processing
Constructing Commands
Modbus Usage in our Products
Modbus RTU Message Structure
Slave/Device ID
Function/Operation
Register
Quantity/Value
Hexadecimal (0x00-0xFF)
0x03 - Read Holding Registers
0x04 - Read Input Registers
0x06 - Write Single Register
0x10 - Write Multiple Registers
Hexadecimal (0x0000-0xFFFF)
Hexadecimal (0x0000-0xFFFF)
Decimal (0-255)
3 - Read Setting
4 - Read Data
6 - Write Setting
16 - Write Setting
Decimal (0-65535)
Hexadecimal (0x0000-0xFFFF)
Register Documentation
Device Type
Grid-tied Inverter
Hybrid Inverter
EPM
All Register Numbers
3000 - Year
3001 - Month
3002 - Day
3003 - Hours
3004 - Mins
3005 - Seconds
3006 - Slave address
3007 - ON/OFF
3008 - Reserve 3009 Power curve No.
3010 - 81>S1
3011 - 81>S1-T
3012 - 81<S1
3013 - 81<S1-T
3014 - 81>S2F
3015 - 81>S2F-T
3016 - 81<S2F
3017 - 81<S2F-T
3018 - 81>S2S
3019 - 81>S2S-T
3020 - 81<S2S
3021 - 81<S2S-T
3022 - Restart Inverter
3023 - DRM S1 Limit 1
3025 - DRM S1 Limit 3
3026 - DRM S1 Limit 4
3027 - DRM ON/OFF
3028 - Restart the HMI
3029 - Inverter installation Method
3030 - Night SVG Q Set
3031 - Remote active power limit percentage
3032 - Reserve
3033 - VRT Enable Switch
3034 - BDEW LVRT K value
3041 - 50549_2 VRT enable
3042 - 50549_2 low voltage ride through mode
3045 - 50549_2 K1 setting value during VRT
3046 - 50549_2 K2 setting value during VRT
3050 - Reserved 3051 Reactive power limitation
3052 - Power limitation
3053 - PF Setting
3054 - PF Setting 02
3055 - Reserve 3056 Calibrate total generation
3058 - Calibrate current month generation
3060 - Calibrate last month generation
3062 - Calibrate today generation
3063 - Calibrate yesterday generation
3064 - Calibrate this year generation
3066 - Calibrate last year generation
3068 - Standard number
3070 - Power limitation switch
3071 - Reactive power switch
3072 - Day Time PID Switch
3073 - Working mode
3074 - Italy Standard Switching Mode
3075 - Italy Single Test
3076 - Italy Full Test
3077 - AFCI ON/OFF
3078 - CT Direction Set
3079 - AFCI Level
3080 - Power control word
3081 - Limit power actual value
3082 - CT Ratio Setting
3083 - Limiting reactive power adjustment value
3084 - Leakage current protection
3085 - PV insulation protection
3086 - Reserve
3087 - ARC_Fault Manual Reset
3088 - VRT Enable Flag bit
3089 - Grid code accuracy set flag
3090 - OV-G-V 01
3091 - OV-G-V-T 01
3092 - OV-G-V 02
3093 - OV-G-V-T 02
3094 - UN-G-V 01
3095 - UN-G-V-T 01
3096 - UN-G-V 02
3097 - UN-G-V-T 02
3098 - OV-G-F 01
3099 - OV-G-F-T 01
3100 - OV-G-F 02
3101 - OV-G-F-T 02
3102 - UN-G-F 01
3103 - UN-G-F-T 01
3104 - UN-G-F 02
3105 - UN-G-F-T 02
3106 - Startup time
3107 - Reconnect time
3108 - Recover V upper limit
3109 - Recover V lower limit
3110 - Recover F upper limit
3111 - Recover F lower limit
3112 - Startup V upper limit
3113 - Startup V lower limit
3114 - Startup F upper limit
3115 - Startup F lower limit
3116 - Denmark Freq Change Protection Threshold
3117 - Denmark Freq Change Protection Time
3118 - Working mode control switch
3119 - OV-G-V03
3120 - OV-G-V03-T
3121 - UN-G-V03
3122 - UN-G-V03-T
3123 - Reserve
3124 - National standard special switch
3126 - Volt-Var Vref Setting
3127 - Volt-Var Vref Time Setting
3128 - 02 working mode V2-Q2 Percent
3129 - 02 working mode V3-Q3 Percent
3130 - 01/06 working mode V1Set
3131 - 01/06 working mode V2Set
3132 - 01/06 working mode V3Set
3133 - 01/06 working mode V4Set
3134 - 01/06 working mode（P1% Set）
3135 - 01/06 working mode（P2% Set）
3136 - 01/06 working mode（P3% Set）
3137 - 01/06 working mode（P4% Set）
3138 - 02 working mode V1Set
3139 - 02 working mode V2Set
3140 - 02 working mode V3Set
3141 - 02 working mode V4Set
3142 - 02 working mode （ MaxLeadingVar%）
3143 - 02 working mode （ MaxLaggingVar%）
3144 - 05 working mode （ Pb% Set）
3145 - 05 working mode （ Pc% Set）
3146 - 05 working mode（PFcSet）
3147 - 10mins over voltage
3148 - Power ramp rate (Wgra), general
3149 - Power ramp up rate
3150 - Power ramp down rate
3156 - Backflow Work mode
3157 - Power Control Slope
3158 - RD244_EPM_ON/OFF setting
3159 - Factory Reset
3160 - Reset 01 Working Mode
3161 - Reset 02 Power rate limit
3162 - Reset 0 Freq Derate Set
3163 - Reset 04 10min overvoltage
3164 - G100 Control Switch
3165 - Backflow Current
3166 - Clear G100 Alarm
3167 - G100 Clear Alarm Type Select
3171 - 05 P-PF working mode -
3177 - enable switch 0055H: represents enable (3177 register function allows setting); 0000H: Function is not enabled; Disabled by default. 3179 Safety Fault&Ride through Switch Set
3180 - Shading MPPT Scan Enable
3181 - Shading MPPT Scan Time interval
3182 - EN50549 Reconnect Slope Limit (Wgra_Rec) setting
3183 - EN50549 Startup Slope Limit（Wgra_nor）setting
3184 - Power Ramp up Slope Limit (Wgra+) setting
3185 - Power Ramp down Slope Limit (Wgra+) setting
3186 - EN50549 P-Lock in
3187 - EN50549 P-Lock out
3190 - Change slope (Wnor)
3201 - FSM power change limit percentage
3202 - Droop settings for FSM
3203 - FSM response dead zone setting
3204 - FSM frequency insensitivity setting
3223 - Actual adjustment value of power limit
3225 - Limited reactive power adjustment value
3230 - Datalogger 1 Connection Status
3231 - Datalogger 2 Connection
3232 - WIFI Signal Strength
3233 - Password Level
3234 - The 1st、2nd digit password
3235 - The 3rd、4th digit password
3236 - The 5th、6th digit password
3238 - IV curve 128 points request flag bits
3239 - IV curve 128 point string number
3247 - AFCI board sub switch
3252 - Learning enable switch
3253 - Self-Learning time setting
3254 - Self-learning result clear switch
3294 - AD debug array
3299 - Calibrate real-time power parameter settings
3301 - Fan self-test
3303 - One Click Reset Operating Command
3304 - Special Function Control Word 01
3305 - Grid V A compensation
3306 - Grid V B compensation
3307 - Grid V C compensation
3308 - Grid V A compensation Rated value
3309 - Grid V B compensation Rated value
3310 - Grid V C compensation Rated value
3311 - Enable “Power ON display to select grid code” Flag
3312 - Special control word 02
3313 - Voltage value in constant voltage Mppt mode
3314 - Grid filter Setting
3315 - Special control word 03
3318 - PCC offset voltage in the case of ule21Phase3
3321 - P_Q Mode P1
3322 - P_Q Mode P2
3323 - P_Q Mode P3
3324 - P_Q Mode P4
3325 - P_Q Mode P5
3326 - P_Q Mode Q1
3327 - P_Q Mode Q2
3328 - P_Q Mode Q3
3329 - P_Q Mode Q4
3330 - P_Q Mode Q5
3331 - Volt Var P3Tau
3332 - Volt Var Q3Tau
3334 - DRM7 Reactive power
3336 - Meter Setting
3337 - Volt Var Qdroop
3338 - Overfrequency load shedding power lower limit percentage
3339 - CT sampling power threshold
3340 - Fan de-icing main switch
3341 - Fan start interval
3342 - Fan de-icing temperature threshold
3344 - Open SVG start time-day
3346 - Enable SVG end time-day
3400 - Frequency Derating Mode
3452 - Special control word 04
3453 - Special control word 05
3500 - External fan start and stop condition switch
3501 - External fan temperature starting point
3502 - External fan temperature stop point
3507 - External fan speed control curve temperature point 1
3508 - External fan speed control curve temperature point 2
3509 - External fan speed control curve speed 1
3510 - External fan speed control curve speed 2
3511 - External fan speed control curve speed 3
All Register Names
01/06 working mode V1Set (3130)
01/06 working mode V2Set (3131)
01/06 working mode V3Set (3132)
01/06 working mode V4Set (3133)
01/06 working mode（P1% Set） (3134)
01/06 working mode（P2% Set） (3135)
01/06 working mode（P3% Set） (3136)
01/06 working mode（P4% Set） (3137)
02 working mode （ MaxLaggingVar%） (3143)
02 working mode （ MaxLeadingVar%） (3142)
02 working mode V1Set (3138)
02 working mode V2-Q2 Percent (3128)
02 working mode V2Set (3139)
02 working mode V3-Q3 Percent (3129)
02 working mode V3Set (3140)
02 working mode V4Set (3141)
05 P-PF working mode - (3171)
05 working mode （ Pb% Set） (3144)
05 working mode （ Pc% Set） (3145)
05 working mode（PFcSet） (3146)
10mins over voltage (3147)
50549_2 K1 setting value during VRT (3045)
50549_2 K2 setting value during VRT (3046)
50549_2 low voltage ride through mode (3042)
50549_2 VRT enable (3041)
81<S1 (3012)
81<S1-T (3013)
81<S2F (3016)
81<S2F-T (3017)
81<S2S (3020)
81<S2S-T (3021)
81>S1 (3010)
81>S1-T (3011)
81>S2F (3014)
81>S2F-T (3015)
81>S2S (3018)
81>S2S-T (3019)
Actual adjustment value of power limit (3223)
AD debug array (3294)
AFCI board sub switch (3247)
AFCI Level (3079)
AFCI ON/OFF (3077)
ARC_Fault Manual Reset (3087)
Backflow Current (3165)
Backflow Work mode (3156)
BDEW LVRT K value (3034)
Calibrate current month generation (3058)
Calibrate last month generation (3060)
Calibrate last year generation (3066)
Calibrate real-time power parameter settings (3299)
Calibrate this year generation (3064)
Calibrate today generation (3062)
Calibrate yesterday generation (3063)
Change slope (Wnor) (3190)
Clear G100 Alarm (3166)
CT Direction Set (3078)
CT Ratio Setting (3082)
CT sampling power threshold (3339)
Datalogger 1 Connection Status (3230)
Datalogger 2 Connection (3231)
Day (3002)
Day Time PID Switch (3072)
Denmark Freq Change Protection Threshold (3116)
Denmark Freq Change Protection Time (3117)
DRM ON/OFF (3027)
DRM S1 Limit 1 (3023)
DRM S1 Limit 3 (3025)
DRM S1 Limit 4 (3026)
DRM7 Reactive power (3334)
Droop settings for FSM (3202)
EN50549 P-Lock in (3186)
EN50549 P-Lock out (3187)
EN50549 Reconnect Slope Limit (Wgra_Rec) setting (3182)
EN50549 Startup Slope Limit（Wgra_nor）setting (3183)
Enable “Power ON display to select grid code” Flag (3311)
Enable SVG end time-day (3346)
enable switch 0055H: represents enable (3177 register function allows setting); 0000H: Function is not enabled; Disabled by default. 3179 Safety Fault&Ride through Switch Set (3177)
External fan speed control curve speed 1 (3509)
External fan speed control curve speed 2 (3510)
External fan speed control curve speed 3 (3511)
External fan speed control curve temperature point 1 (3507)
External fan speed control curve temperature point 2 (3508)
External fan start and stop condition switch (3500)
External fan temperature starting point (3501)
External fan temperature stop point (3502)
Factory Reset (3159)
Fan de-icing main switch (3340)
Fan de-icing temperature threshold (3342)
Fan self-test (3301)
Fan start interval (3341)
Frequency Derating Mode (3400)
FSM frequency insensitivity setting (3204)
FSM power change limit percentage (3201)
FSM response dead zone setting (3203)
G100 Clear Alarm Type Select (3167)
G100 Control Switch (3164)
Grid code accuracy set flag (3089)
Grid filter Setting (3314)
Grid V A compensation (3305)
Grid V A compensation Rated value (3308)
Grid V B compensation (3306)
Grid V B compensation Rated value (3309)
Grid V C compensation (3307)
Grid V C compensation Rated value (3310)
Hours (3003)
Inverter installation Method (3029)
Italy Full Test (3076)
Italy Single Test (3075)
Italy Standard Switching Mode (3074)
IV curve 128 point string number (3239)
IV curve 128 points request flag bits (3238)
Leakage current protection (3084)
Learning enable switch (3252)
Limit power actual value (3081)
Limited reactive power adjustment value (3225)
Limiting reactive power adjustment value (3083)
Meter Setting (3336)
Mins (3004)
Month (3001)
National standard special switch (3124)
Night SVG Q Set (3030)
ON/OFF (3007)
One Click Reset Operating Command (3303)
Open SVG start time-day (3344)
OV-G-F 01 (3098)
OV-G-F 02 (3100)
OV-G-F-T 01 (3099)
OV-G-F-T 02 (3101)
OV-G-V 01 (3090)
OV-G-V 02 (3092)
OV-G-V-T 01 (3091)
OV-G-V-T 02 (3093)
OV-G-V03 (3119)
OV-G-V03-T (3120)
Overfrequency load shedding power lower limit percentage (3338)
P_Q Mode P1 (3321)
P_Q Mode P2 (3322)
P_Q Mode P3 (3323)
P_Q Mode P4 (3324)
P_Q Mode P5 (3325)
P_Q Mode Q1 (3326)
P_Q Mode Q2 (3327)
P_Q Mode Q3 (3328)
P_Q Mode Q4 (3329)
P_Q Mode Q5 (3330)
Password Level (3233)
PCC offset voltage in the case of ule21Phase3 (3318)
PF Setting (3053)
PF Setting 02 (3054)
Power Control Slope (3157)
Power control word (3080)
Power limitation (3052)
Power limitation switch (3070)
Power ramp down rate (3150)
Power Ramp down Slope Limit (Wgra+) setting (3185)
Power ramp rate (Wgra), general (3148)
Power ramp up rate (3149)
Power Ramp up Slope Limit (Wgra+) setting (3184)
PV insulation protection (3085)
RD244_EPM_ON/OFF setting (3158)
Reactive power switch (3071)
Reconnect time (3107)
Recover F lower limit (3111)
Recover F upper limit (3110)
Recover V lower limit (3109)
Recover V upper limit (3108)
Remote active power limit percentage (3031)
Reserve (3032)
Reserve (3086)
Reserve (3123)
Reserve 3009 Power curve No. (3008)
Reserve 3056 Calibrate total generation (3055)
Reserved 3051 Reactive power limitation (3050)
Reset 0 Freq Derate Set (3162)
Reset 01 Working Mode (3160)
Reset 02 Power rate limit (3161)
Reset 04 10min overvoltage (3163)
Restart Inverter (3022)
Restart the HMI (3028)
Seconds (3005)
Self-learning result clear switch (3254)
Self-Learning time setting (3253)
Shading MPPT Scan Enable (3180)
Shading MPPT Scan Time interval (3181)
Slave address (3006)
Special control word 02 (3312)
Special control word 03 (3315)
Special control word 04 (3452)
Special control word 05 (3453)
Special Function Control Word 01 (3304)
Standard number (3068)
Startup F lower limit (3115)
Startup F upper limit (3114)
Startup time (3106)
Startup V lower limit (3113)
Startup V upper limit (3112)
The 1st、2nd digit password (3234)
The 3rd、4th digit password (3235)
The 5th、6th digit password (3236)
UN-G-F 01 (3102)
UN-G-F 02 (3104)
UN-G-F-T 01 (3103)
UN-G-F-T 02 (3105)
UN-G-V 01 (3094)
UN-G-V 02 (3096)
UN-G-V-T 01 (3095)
UN-G-V-T 02 (3097)
UN-G-V03 (3121)
UN-G-V03-T (3122)
Volt Var P3Tau (3331)
Volt Var Q3Tau (3332)
Volt Var Qdroop (3337)
Volt-Var Vref Setting (3126)
Volt-Var Vref Time Setting (3127)
Voltage value in constant voltage Mppt mode (3313)
VRT Enable Flag bit (3088)
VRT Enable Switch (3033)
WIFI Signal Strength (3232)
Working mode (3073)
Working mode control switch (3118)
Year (3000)
Register address
name
Data type
Unit
Remark
Address type
3000
Year
U16
-
00-99
Note:
For function codes 0x03, 0x06 and 0x10, the register address needs to offset one bit.
Example: register address: 3000, the send address is 2999.
Generated Command:
Show spaces
01
03
0BB7
0001
3608
Copy
Parse Modbus Command
Enter the Modbus command in - to check what the command does.
Parse Modbus Reply
Enter the Modbus reply to parse the register values.