WEG CFW500 drive
Register map(s) for this device, with a note of how far each has been checked. Addresses are
0-based, as on the wire. Scale and byte order are confirmed only at the hardware-verified rung.
coherence-checked
Round-trips through a real Modbus stack with no overlapping addresses and a word-order-sensitive codec — the map is internally coherent and wire-decodable. Does NOT prove byte-order or scaling match a real device: the emulator is seeded from the map's own types, so a uniformly wrong byte-order still round-trips. Only hardware-verified confirms byte-order/scale on the wire.
| point | address (0-based) | type | scale | unit |
|---|
| serial_interf_status | 316 | U16 | 1 | |
| logical_status | 680 | U16 | 1 | |
| speed_in_13_bits | 681 | I16 | 1 | |
| serial_usb_control | 682 | U16 | 1 | |
| serial_usb_speed_ref | 683 | I16 | 1 | |
| dox_value | 695 | U16 | 1 | |
| aox_value_1 | 696 | I16 | 1 | % |
| aox_value_2 | 697 | I16 | 1 | % |
| aox_value_3 | 698 | I16 | 1 | % |
link settings as documented (unverified): RTU; default 19200 8E1; unit ID 1; FC 01,02,03,04,05,06,15,16,43
bench facts as documented (unverified)
| terminals | Pin 14: RS485-A(-), Pin 16: RS485-B(+), Pin 18: GND |
| A/B polarity | Pin 14 is A(-), Pin 16 is B(+) |
| termination | 120 Ohm | 0.25 W resistor connected between +B and -A |
| connector | Control terminal (CFW500-IOS), mini-USB (CFW500-CUSB), DB9 (CFW500-CRS232) |
| isolation | Galvanically insulated |
| shield/ground | Shielded cable with twisted pair, shield must be grounded |
| broadcast | supported |
| FC 43 device ID | supported |
| doc revision | 04 |
field reports — community-sourced, unverified (checked 2026-06-11)
- The Modbus RTU telegrams for request and response cannot exceed 64 bytes. Attempting to read large blocks of registers (e.g., up to 125 registers) will fail due to this buffer limit. [source]
- In firmware versions prior to V4.1X, attempting to read a range of registers that includes a missing or skipped parameter (e.g., reading from P0007 to P0009 where P0008 is skipped) causes the drive to return an error or nothing for all parameters in that range. Firmware V4.1X resolved this by adding support for Modbus read/write continuity even with invalid addresses in the sequence. [source]
- confirmed: comms defaults (baud rates [9600, 19200, 38400], default baud 19200, default unit ID 1, RTU framing, parity E, stop bits 1) — confirmed by WEG CFW500 Modbus RTU User's Guide (Doc 10002253377, Rev 04) parameters P0308, P0310, and P0311
- confirmed: supported Modbus function codes (1, 2, 3, 4, 5, 6, 15, 16, 43) — confirmed by Table 5.1 of the Modbus RTU CFW500 User's Guide
- confirmed: physical connector options (Control terminal CFW500-IOS, mini-USB CFW500-CUSB, DB9 CFW500-CRS232) — confirmed by Section 2 of the Modbus RTU CFW500 User's Guide
- confirmed: RS485 terminals and polarity (Pin 14 is A(-), Pin 16 is B(+), Pin 18 is GND) — confirmed by Table 2.1 of the Modbus RTU CFW500 User's Guide
- confirmed: termination resistor (120 Ohm | 0.25 W connected between +B and -A) — confirmed by Section 3.3 of the Modbus RTU CFW500 User's Guide
- confirmed: broadcast supported on address 0 — confirmed by Section 1.1 of the Modbus RTU CFW500 User's Guide
- confirmed: register map summary (serial_interf_status @ 316, logical_status @ 680, speed_in_13_bits @ 681, serial_usb_control @ 682, serial_usb_speed_ref @ 683, dox_value @ 695, aox_value_1 @ 696, aox_value_2 @ 697, aox_value_3 @ 698) — confirmed by the parameter list and Modbus RTU memory map where parameter numbers map directly to 0-based Modbus addresses
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.
- coherence-checked — Round-trips through a real Modbus stack with no overlapping addresses and a word-order-sensitive codec — the map is internally coherent and wire-decodable. Does NOT prove byte-order or scaling match a real device: the emulator is seeded from the map's own types, so a uniformly wrong byte-order still round-trips. Only hardware-verified confirms byte-order/scale on the wire.
- hardware-verified (software-key) x1 — Matched a real device with operator-attested readings as ground truth — the only rung that confirms word order + scaling on the wire.