==== Modbus communication ====
**Read Limits:** Do not attempt to read more than 40 parameters (80 registers) in a single Modbus request to avoid exception errors.

RS485 communication interface, MODBUS RTU protocol:
  * Baudrate: 9600 Baud (default, can be set)
  * Parity: Even
  * Databits: 8
  * Stopbits: 1
  * Default slave ID: 1 (SMD72D), 45 (SDM72CTM)
  * Number of Drivers and Receivers: 32 Drivers, 32 Receivers (without repeater)
  * Maximum Cable Length: 1200 m
  * Maximum Data Rate: 10 Mbaud
  * Maximum Common Mode Voltage: 12 V .. –7 V
  * Minimum Driver Output Levels (Loaded): +/– 1.5 V
  * Minimum Driver Output Levels (Unloaded): +/– 6 V
  * Drive Load: Minimum 60 ohms
  * Driver Output Short Circuit Current Limit: 150 mA to Gnd, 250 mA to 12 V, 250 mA to -7 V
  * Minimum Receiver Input Resistance: 12 kΩ 
  * Receiver Sensitivity: +/- 200 mV

==== Convert word array to real array ====
The Input registers are in a word format and must be converted into real numbers in pairs. This conversion involves straightforward bit-level merging, which can be implemented in LabView, for example, as shown below: 

{{:sensor:conv_word_array_to_real_array_labview.png|Convert word array (input registers) to real array in labView}}

==== 32-bit (2 words) input registers ====
The registers are read-only. All values are 4-byte IEEE 754 float type.
|< 100% 10% 10% 70% 10% >|
^Register Nr^32 bit address^Description^Unit^Type|
|30001|1|Phase 1 line to neutral volts|Volts|SDM630, SDM230|
|30003|2|Phase 2 line to neutral volts|Volts|
|30005|3|Phase 3 line to neutral volts|Volts|
|30007|4|Phase 1 current|Amps|SDM630, SDM230|
|30009|5|Phase 2 current|Amps|SDM630|
|30011|6|Phase 3 current|Amps|SDM630|
|30013|7|Active Power Phase 1|Watts|SDM630, SDM230|
|30015|8|Active Power Phase 2|Watts|SDM630|
|30017|9|Active Power Phase 3|Watts|SDM630|
|30019|10|Apparent power Phase 1|VA|SDM630, SDM230|
|30021|11|Apparent power Phase 2|VA|SDM630|
|30023|12|Apparent power Phase 3|VA|SDM630|
|30025|13|Phase 1 volt amps reactive|VAr|SDM630, SDM230|
|30027|14|Phase 2 volt amps reactive|VAr|SDM630|
|30029|15|Phase 3 volt amps reactive|VAr|SDM630|
|30031|16|Reactive power Phase 1 \\ (pos: forward current, neg: reverse current)|-|SDM630, SDM230|
|30033|17|Reactive power Phase 2 \\ (pos: forward current, neg: reverse current)|-|SDM630|
|30035|18|Reactive power Phase 3 \\ (pos: forward current, neg: reverse current)|-|SDM630|
|30037|19|Phase 1 phase angle|Degrees|SDM630, SDM230|
|30039|20|Phase 2 phase angle|Degrees|SDM630|
|30041|21|Phase 3 phase angle|Degrees|SDM630|
|30043|22|Average line to neutral volts|Volts|SDM630|
|30047|24|Average line current|Amps|SDM630|
|30049|25|Sum of line currents|Amps|SDM630|
|30053|27|Total system power|Watts|SDM630|
|30057|29|Total system volt amps|VA|SDM630|
|30061|31|Total system power factor|VAr|SDM630|
|30063|32|Total system power factor \\ (pos: forward current, neg: reverse current)|-|SDM630|
|30067|34|Total system phase angle|Degrees|SDM630|
|30071|36|Frequency of supply voltages|Hz|SDM630, SDM230|
|30073|37|Total Import Energy|kWh|SDM630, SDM230|
|30075|38|Total Export Energy|kWh|SDM630, SDM230|
|30077|39|Total Import Reactive Energy|kVArh|SDM630, SDM230|
|30079|40|Total Export Reactive Energy|kVArh|SDM630, SDM230|
|30081|41|Total Power|kVAh|SDM630|
|30083|42|Current Hour|Ah|SDM630|
|30085|43|Total system power demand \\ (power sum demand calculation is for import – export)|W|SDM630, SDM230|
|30087|44|Maximum total system power demand \\ (power sum demand calculation is for import – export)|VA|SDM630, SDM230|
|30089|45|Current system positive power demand|W|SDM630, SDM230|
|30091|46|Maximum system positive power demand|W|SDM630, SDM230|
|30093|47|Current system reverse power demand|W|SDM630, SDM230|
|30095|48|Maximum system reverse power demand|W|SDM630, SDM230|
|30101|51|Total system VA demand|VA|SDM630|
|30103|52|Maximum total system VA demand|VA|SDM630|
|30105|53|Neutral current demand|Amps|SDM630|
|30107|54|Maximum neutral current demand|Amps|SDM630|
|30201|101|Line 1 to Line 2 volts|Volts|SDM630|
|30203|102|Line 2 to Line 3 volts|Volts|SDM630|
|30205|103|Line 3 to Line 1 volts|Volts|SDM630|
|30207|104|Average line to line volts|Volts|SDM630|
|30225|113|Neutral current|Amps|SDM630|
|30235|118|Phase 1 L/N volts THD|%|SDM630|
|30237|119|Phase 2 L/N volts THD|%|SDM630|
|30239|120|Phase 3 L/N volts THD|%|SDM630|
|30241|121|Phase 1 Current THD|%|SDM630|
|30243|122|Phase 2 Current THD|%|SDM630|
|30245|123|Phase 3 Current THD|%|SDM630|
|30249|125|Average line to neutral volts THD|%|SDM630|
|30251|126|Average line current THD|%|SDM630|
|30259|130|Phase 1 current demand|Amps|SDM630, SDM230|
|30261|131|Phase 2 current demand|Amps|SDM630|
|30263|132|Phase 3 current demand|Amps|SDM630|
|30265|133|Maximum phase 1 current demand|Amps|SDM630, SDM230|
|30267|134|Maximum phase 2 current demand|Amps|SDM630|
|30269|135|Maximum phase 3 current demand|Amps|SDM630|
|30335|168|Line 1 to line 2 volts THD|%|SDM630|
|30337|169|Line 2 to line 3 volts THD|%|SDM630|
|30339|170|Line 3 to line 1 volts THD|%|SDM630|
|30341|171|Average line to line volts THD|%|SDM630|
|30343|172|Total active energy \\ (total kWh / kVarh equals Import + export)|kWh|SDM630, SDM230|
|30345|173|Total reactive energy \\ (total kWh / kVarh equals Import + export)|kvarh|SDM630, SDM230|
|30347|174|L1 import active energy|kWh|SDM630|
|30349|175|L2 import active energy|kWh|SDM630|
|30351|176|L3 import active energy|kWh|SDM630|
|30353|177|L1 export active energy|kWh|SDM630|
|30355|178|L2 export active energy|kWh|SDM630|
|30357|179|L3 export active energy|kwh|SDM630|
|30359|180|L1 total active energy \\ (total kWh / kVarh equals Import + export)|kwh|SDM630|
|30361|181|L2 total active energy \\ (total kWh / kVarh equals Import + export)|kwh|SDM630|
|30363|182|L3 total active energy \\ (total kWh / kVarh equals Import + export)|kwh|SDM630|
|30365|183|L1 import reactive energy|kvarh|SDM630|
|30367|184|L2 import reactive energy|kvarh|SDM630|
|30369|185|L3 import reactive energy|kvarh|SDM630|
|30371|186|L1 export reactive energy|kvarh|SDM630|
|30373|187|L2 export reactive energy|kvarh|SDM630|
|30375|188|L3 export reactive energy|kvarh|SDM630|
|30377|189|L1 total reactive energy \\ (total kWh / kVarh equals Import + export)|kvarh|SDM630|
|30379|190|L2 total reactive energy \\ (total kWh / kVarh equals Import + export)|kvarh|SDM630|
|30381|191|L3 total reactive energy \\ (total kWh / kVarh equals Import + export)|kvarh|SDM630|
|30385|193|Current resettable total active energy|kWh|SDM630, SDM230|
|30387|194|Current resettable total reactive energy|kvarh|SDM630, SDM230|

Source: https://www.eastroneurope.com/images/uploads/products/protocol/SDM630_MODBUS_Protocol.pdf

{{ :meas:sdm630.csv |SDM630/SDM230 Modbus Import registers in .csv file-format}}


{{page>:tarhal}}

==== 32-bit (2 words) holding registers ====
The registers are read/write.

|< 100% 10% 10% 10% 40% 20% 10%>|
^Address register^Parameter number^Parameter^Valid range^type^mode|
|40003|2|Demand period|Write demand period: 0, 5,8, 10, 15, 20, 30, or 60 minutes, default 60. Setting the period to 0 will cause the demand to show the current parameter value, and demand max to show the maximum parameter value since the last demand reset.|Length: 4 byte, Data Format: Float|rw|
|40011|6|System type|Write system type: 3p4w = 3, 3p3w = 2 & 1p2w= 1 Requires password, see parameter 13|Length : 4 byte, Data Format : Float|rw|
|40013|7|Pulse 1 width|Write pulse1 on period in milliseconds: 60, 100, or 200, default 100.|Length: 4 byte, Data Format: Float|r|
|40015|8|Password lock|Write any value to password lock-protected registers. Read password lock status: 0 = locked. 1 = unlocked. Reading will also reset the password timeout back to one minute.|Length: 4 byte, Data Format: Float|r|
|40019|10|Network Parity Stop|Write the network port parity/stop bits for MODBUS Protocol, where: 0 = One stop bit and no parity, default. 1 = One stop bit and even parity. 2 = One stop bit and odd parity.3 = Two stop bits and no parity.Requires a restart to become effective.|Length : 4 byte, Data Format : Float|rw|
|40021|11|Network Node|Write the network port node address: 1 to 247 for MODBUS Protocol, default 1. Requires a restart to become effective.|Length : 4 byte, Data Format : Float|rw|
|40023|12|Pulse1 Divisor1|Write pulse divisor index: n = 0 to 5 \\ 0: 0.0025 kWh(kVArh)/imp \\ 1: 0.01 kWh(kVArh)/imp \\ 2: 0.1 kWh(kVArh)/imp \\ 3: 1 kWh(kVArh)/imp \\ 4: 10 kWh(kVArh)/imp \\ 5: 100 kWh(kVArh)/imp|Length : 4 byte, Data Format : Float|rw|
|40025|13|Password|Write password for access to protected registers. Default: 0000|Length: 4 byte, Data Format: Float|rw|
|40029|15|Network Baud Rate|Write the network port baud rate for MODBUS Protocol, where: \\ 0: 2400 baud \\ 1: 4800 baud \\ 2: 9600 baud, default \\ 3: 19200 baud \\ 4: 38400 baud \\ Requires a restart to become effective|Length: 4 byte, Data Format: Float|rw|
|40087|44|Pulse 1 Energy Type|Write MODBUS Protocol input parameter for pulse output 1: \\ 1: import active energy \\ 2: total active energy \\ 4: export active energy, default \\ 5: import reactive energy \\ 6: total reactive energy \\ 8: export reactive energy|Length : 4 byte, Data Format : Float|rw|
|461457|30729|reset|00 00 ：reset the Maximum demand|Length : 2 byte, Data Format : Hex|w|