Allen-Bradley PowerFlex 520-series drive
Register map(s) for this device, each at the trust rung it earned. Addresses are 0-based
as on the wire. Word order and scaling are confirmed at the hardware-verified rung and at no rung below it.
interop-verified
Read + decoded cleanly over a real network vs an independent third-party Modbus test server (transport and framing; reads are remapped into the server's register window, so the map's own addresses are NOT exercised). Does NOT prove word order/scaling against the actual device.
| point | address (0-based) | type | scale | unit |
|---|
| output_frequency | 0 | U16 | 0.01 | |
| commanded_frequency | 1 | U16 | 0.01 | |
| output_current | 2 | U16 | 0.01 | |
| output_voltage | 3 | U16 | 0.1 | |
| dc_bus_voltage | 4 | U16 | 1 | |
| output_power | 16 | U16 | 0.01 | |
link settings as documented (unverified): RTU; default 9600 8N1; unit ID 100; The RS-485 Multi-drive network is fixed at 19.2K baud rate, 8 data bits, no parity, and 1 stop bit.
bench facts as documented (unverified)
| terminals | DSI port |
| termination | AK-U0-RJ45-TB2P connector with terminating resistor (120 Ω) |
| connector | RJ-45 |
| wiring notes | DSI port is an RS485 cable connection for handheld and remote options. |
| protocol notes | Multi-drive mode allows up to five drives to share a single EtherNet/IP node using RS-485. |
| identification notes | Modbus node address is set via parameter C124 [RS485 Node Addr]. |
| power | The embedded EtherNet/IP adapter receives power from the drive. |
| doc revision | 520COM-UM001B-EN-E - March 2013 |
field reports — community-sourced, unverified (checked 2026-06-11)
- When using Modbus TCP communication on the embedded EtherNet/IP port, the drive ignores commands if the Modbus Unit ID / Slave ID is set to 1 (the typical default). It must be set to 255 or 0 depending on the firmware version. [source]
- The PowerFlex 525 Embedded EtherNet/IP User Manual (520COM-UM001) incorrectly lists the Reference and Feedback registers as N42:2, whereas they are actually at N42:3. [source]
- confirmed: Baud rates [1200, 2400, 4800, 9600, 19200, 38400] and default baud 9600 — confirmed by parameter C123 [RS485 Data Rate] options and default value in Rockwell Automation Publication 520COM-UM001B-EN-E
- confirmed: Default unit ID 100 — confirmed by parameter C124 [RS485 Node Addr] default value in Rockwell Automation Publication 520COM-UM001B-EN-E
- confirmed: Framing RTU, Parity N, Stop bits 1 — confirmed by parameter C127 [RS485 Format] default option 'RTU 8-N-1' in Rockwell Automation Publication 520COM-UM001B-EN-E
- confirmed: The RS-485 Multi-drive network is fixed at 19.2K baud rate, 8 data bits, no parity, and 1 stop bit — confirmed by Rockwell Automation Multi-Drive Configuration guides
- confirmed: Modbus node address is set via parameter C124 [RS485 Node Addr] — confirmed by parameter C124 description in Rockwell Automation Publication 520COM-UM001B-EN-E
- confirmed: DSI port is an RS485 cable connection for handheld and remote options, using RJ-45 connector and AK-U0-RJ45-TB2P connector with 120 Ω terminating resistor — confirmed by PowerFlex 520-Series User Manual (520-UM001)
- confirmed: Multi-drive mode allows up to five drives to share a single EtherNet/IP node using RS-485 — confirmed by Rockwell Automation Publication 520COM-UM001B-EN-E Chapter 7
- confirmed: Register map summary (output_frequency @ 0, commanded_frequency @ 1, output_current @ 2, output_voltage @ 3, dc_bus_voltage @ 4, output_power @ 16) — confirmed by PowerFlex 520-Series parameter-to-Modbus mapping where register address equals parameter number (b001 to b005 and b017) minus 1 for 0-based addressing
The trust ladder
Each rung states what it proved and what it did not. Gray until proven; green is earned by hardware only.
- generated — A prompt produced it. Unproven — anyone can regenerate this.
- structure-verified — Decode path is structurally sound (addresses, widths, finite values). Does NOT prove word order or scaling.
- interop-verified — Read + decoded cleanly over a real network vs an independent third-party Modbus test server (transport and framing; reads are remapped into the server's register window, so the map's own addresses are NOT exercised). Does NOT prove word order/scaling against the actual device.
- simulator-verified — Decoded correctly against a protocol emulator seeded with known-true values — catches word-order/scaling errors vs the emulator, not the physical device.
- hardware-verified x1 — Matched a real device with operator-attested readings as ground truth — the only rung that confirms word order + scaling on the wire.