Siemens · VFD
SINAMICS V20 (V20 inverter, USS/MODBUS on RS485) Modbus register map
Default configuration
- Protocol
- RS485
- Port
- 502
- Unit ID
- 1
- Addressing
- 0-based
- Byte order
- Big endian
- Word order
- High word first
- Baud rate
- 9600
- Parity
- Even
- Data bits
- 8
- Stop bits
- 1
This device has an RS-485 interface. Reach it through a Modbus RTU-to-TCP gateway, configured with the factory serial settings above.
Register map
| Address | Count | Name | Type | Unit | Scale | Access |
|---|---|---|---|---|---|---|
| 0 | 1 | Watchdog time Range 0-65535 ms (register 40001). | UInt16 | ms | 1 | RW |
| 1 | 1 | Watchdog action Range 0-1 (40002). | UInt16 | - | 1 | RW |
| 2 | 1 | Frequency setpoint Scaling 100, range 0.00-100.00 % (40003). The manual maps it onto control word bits STW:3/STW:11. | UInt16 | % | 0.01 | RW |
| 3 | 1 | Run enable Range 0-1; mapped onto STW:3 (40004). | UInt16 | - | 1 | RW |
| 4 | 1 | Forward/reverse command Range 0-1; mapped onto STW:11 (40005). | UInt16 | - | 1 | RW |
| 5 | 1 | Start command Range 0-1; mapped onto STW:0 (40006). | UInt16 | - | 1 | RW |
| 6 | 1 | Fault acknowledgement Range 0-1; mapped onto STW:7 (40007). | UInt16 | - | 1 | RW |
| 7 | 1 | PID setpoint reference Scaling 100, range -200.0 to 200.0 % (40008). | Int16 | % | 0.01 | RW |
| 8 | 1 | PID enable Range 0-1 (40009). | UInt16 | - | 1 | RW |
| 9 | 1 | Current limit Scaling 10, range 10.0 to 400.0 % (40010). | UInt16 | % | 0.1 | RW |
| 10 | 1 | Acceleration time Scaling 100, range 0.00 to 650.0 s (40011). | UInt16 | s | 0.01 | RW |
| 11 | 1 | Deceleration time Scaling 100, range 0.00 to 650.0 s (40012). | UInt16 | s | 0.01 | RW |
| 13 | 1 | Digital output 1 HIGH/LOW (40014); mapped onto r0747.0 / P0731. | UInt16 | - | 1 | RW |
| 14 | 1 | Digital output 2 HIGH/LOW (40015); mapped onto r0747.1 / P0732. | UInt16 | - | 1 | RW |
| 15 | 1 | Reference frequency Scaling 100, range 1.00 to 550.00 Hz (40016). | UInt16 | Hz | 0.01 | RW |
| 16 | 1 | PID upper limit Scaling 100, range -200.0 to 200.0 % (40017). | Int16 | % | 0.01 | RW |
| 17 | 1 | PID lower limit Scaling 100, range -200.0 to 200.0 % (40018). | Int16 | % | 0.01 | RW |
| 18 | 1 | Proportional gain Scaling 1000, range 0.000 to 65.000 (40019). | UInt16 | - | 0.001 | RW |
| 19 | 1 | Integral gain Range 0-60 s (40020). | UInt16 | s | 1 | RW |
| 33 | 1 | Forward/reverse FWD/REV status bit ZSW:14 (40034). | UInt16 | - | 1 | R |
| 34 | 1 | Stop/run STOP/RUN status bit ZSW:2 (40035). | UInt16 | - | 1 | R |
| 35 | 1 | Run at maximum frequency MAX/NO status bit ZSW:10 (40036). | UInt16 | - | 1 | R |
| 36 | 1 | Control mode SERIAL/LOCAL status bit ZSW:9 (40037). | UInt16 | - | 1 | R |
| 37 | 1 | Enabled ON/OFF status bit ZSW:0 (40038). | UInt16 | - | 1 | R |
| 38 | 1 | Ready to run READY/OFF status bit ZSW:1 (40039). | UInt16 | - | 1 | R |
| 47 | 1 | Digital input 1 HIGH/LOW (40048), r0722.0. | UInt16 | - | 1 | R |
| 48 | 1 | Digital input 2 HIGH/LOW (40049), r0722.1. | UInt16 | - | 1 | R |
| 49 | 1 | Digital input 3 HIGH/LOW (40050), r0722.2. | UInt16 | - | 1 | R |
| 50 | 1 | Digital input 4 HIGH/LOW (40051), r0722.3. | UInt16 | - | 1 | R |
| 100 | 1 | HSW (speed setpoint, process data) PZD word 2 (40101). | UInt16 | - | 1 | RW |
| 109 | 1 | ZSW (status word, process data) PZD word 1 (40110). | UInt16 | - | 1 | R |
| 110 | 1 | HIW (actual speed, process data) PZD word 2 (40111). | UInt16 | - | 1 | R |
| 219 | 1 | Analog output 1 Scaling 100, range -100.0 to 100.0 % (40220). | Int16 | % | 0.01 | R |
| 239 | 1 | Digital input 1 (process data) HIGH/LOW (40240), r0722.0; the same value as register 47. | UInt16 | - | 1 | R |
| 240 | 1 | Digital input 2 (process data) HIGH/LOW (40241), r0722.1. | UInt16 | - | 1 | R |
| 241 | 1 | Digital input 3 (process data) HIGH/LOW (40242), r0722.2. | UInt16 | - | 1 | R |
| 242 | 1 | Digital input 4 (process data) HIGH/LOW (40243), r0722.3. | UInt16 | - | 1 | R |
| 243 | 1 | Digital input 5 (process data) HIGH/LOW (40244), r0722.4; available with the optional I/O extension module. | UInt16 | - | 1 | R |
| 244 | 1 | Digital input 6 (process data) HIGH/LOW (40245), r0722.5; available with the optional I/O extension module. | UInt16 | - | 1 | R |
| 259 | 1 | Analog input 1 Scaling 100, range -300.0 to 300.0 % (40260). | Int16 | % | 0.01 | R |
| 260 | 1 | Analog input 2 Scaling 100, range -300.0 to 300.0 % (40261). | Int16 | % | 0.01 | R |
| 299 | 1 | Inverter model Range 0-32767 (40300), r0201. | UInt16 | - | 1 | R |
| 300 | 1 | Inverter version Scaling 100, range 0.00 to 327.67 (40301), r0018. | UInt16 | - | 0.01 | R |
| 319 | 1 | Rated power Scaling 100, range 0 to 327.67 kW (40320), r0206. | UInt16 | kW | 0.01 | R |
| 339 | 1 | Reference Scaling 100, range -327.68 to 327.67 Hz (40340), r0020. | Int16 | Hz | 0.01 | R |
| 340 | 1 | Speed Range -16250 to 16250 RPM (40341), r0022. | Int16 | RPM | 1 | R |
| 341 | 1 | Frequency output Scaling 100, range -327.68 to 327.67 Hz (40342), r0024. | Int16 | Hz | 0.01 | R |
| 342 | 1 | Voltage output Range 0-32767 V (40343), r0025. | UInt16 | V | 1 | R |
| 343 | 1 | DC bus voltage Range 0-32767 V (40344), r0026. | UInt16 | V | 1 | R |
| 344 | 1 | Current, filtered Scaling 100, range 0 to 163.83 A (40345), r0027. | UInt16 | A | 0.01 | R |
| 345 | 1 | Torque Scaling 100, range -325.00 to 325.00 Nm (40346), r0031. | Int16 | Nm | 0.01 | R |
| 346 | 1 | Actual power Scaling 100, range 0 to 327.67 kW (40347), r0032. | UInt16 | kW | 0.01 | R |
| 347 | 1 | Total kWh Range 0-32767 kWh (40348), r0039. | UInt16 | kWh | 1 | R |
| 348 | 1 | Hand/auto HAND/AUTO (40349), r0807. | UInt16 | - | 1 | R |
| 349 | 1 | Current, unfiltered Scaling 100, range 0 to 163.83 A (40350), r0068. | UInt16 | A | 0.01 | R |
| 399 | 1 | Fault 1 Range 0-32767 (40400), r0947[0]. | UInt16 | - | 1 | R |
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Related guides
Notes
RS-485 compact drive: Modbus RTU on the inverter's RS485 interface (terminal or RS485/USB cable), reached through a Modbus RTU-to-TCP gateway, so the serial block records the factory frame. Source: Siemens "SINAMICS V20 Inverter - Operating Instructions" 01/2018, A5E34559884-009, section 7.2 "MODBUS communication" - "Mapping table" (pages 177-179) and the parameter table on pages 176-177 (P2010 baud rate, P2021 MODBUS address, P2023 RS485 protocol, P2034 parity, P2035 stop bits). Factory frame: P2021 = 1 (address), P2010 = 6 (9600 bit/s), P2034 = 2 (even parity) and P2035 = 1 (1 stop bit), which is 9600 8E1. The RS485 protocol is not Modbus at the factory - P2023 defaults to 1 (USS) - so P2023 must be set to 2 (Modbus RTU) and the inverter power-cycled; that is what connection macro Cn011 does. Addressing: the mapping table prints a zero-based "Register No." column beside the Modbus reference (register 0 = 40001), so this seed stores the Register No. column with zero-based addressing. Scaling follows the table's "Scaling factor" column: 100 becomes 0.01, 10 becomes 0.1, 1000 becomes 0.001, and a factor of 1 stays 1. The table prints the same measurement in more than one block (for example speed at register 24 and 340, total kWh at 28 and 347); this seed keeps the process-data block at 339-350 and the control block at 0-19. Rows 20-32, 40-46, 51 and 54-61 are left out as a scope choice: 23-32 and 43 repeat values the seed already lists at another address, 40-42 and 54-61 repeat the analog and fault/warning rows, while the PID gains at 20-22 and the PID outputs at 44-46 are unique registers this seed does not cover. Registers marked * in the table (13/14 partly, 201-202, 243-244) need the optional I/O extension module; the descriptions say so. The inverter needs P0700/P1000 = 5 (USS/MODBUS on RS485) for the control word and setpoints above to act, which is a commissioning step, not a register.