Fit a FENA-11/-21, set 50.01 = its slot, 51.02 = 1 (MB/TCP ABB E), a static IP in 51.04–51.13, 51.20 timeout and 51.27 refresh. Set 20.01 = Fieldbus A and 22.11 = FB A ref1. The client writes CW to 400001 and Ref1 to 400002, and reads SW at 400051 and Act1 at 400052, on TCP port 502.
Network and roles
The FENA adapter makes the drive a Modbus TCP server. A PLC, SCADA or HMI is the client and opens a connection to the drive's IP address on port 502. Several clients can read the same drive; only one should write the control word.
Drive parameters
Defaults and options are from the ABB FENA-01/-11/-21 user's manual; the ACS580 uses group 51 for adapter settings, 52 for data in and 53 for data out.
| Parameter | Name | Set to | Why |
|---|---|---|---|
50.01 | FBA A enable | Option slot of the FENA | Activates the adapter |
50.02 / 50.03 | Comm loss func / time | Fault, 3.0 s (example) | Drive reaction to a lost client |
51.02 | Protocol/Profile | 1 = MB/TCP ABB E | Modbus/TCP, ABB Drives Enhanced profile |
51.03 | Commrate | 0 = Auto | Auto-negotiate speed and duplex |
51.04 | IP configuration | 0 = Static IP | Default is DHCP; use static for PLCs |
51.05–51.08 | IP address 1–4 | e.g. 192.168.0.16 | One octet per parameter |
51.09 | Subnet CIDR | 24 | = 255.255.255.0 |
51.10–51.13 | Gateway 1–4 | e.g. 192.168.0.1 | Only if routing to another subnet |
51.20 | Modbus/TCP timeout | 10 | ×100 ms = 1 s |
51.21 | Timeout mode | 2 = Control RW | Timer resets on new CW or Ref |
51.22 | Word order | 1 = HiLo (default) | 32-bit value order |
51.23 | Address mode | 0 = Mode 0 | Parameter = 100 × group + index |
52.01… | Data in 1… | e.g. 01.07 motor current | Extra values to the client (400054…) |
53.01… | Data out 1… | e.g. a setpoint parameter | Extra values from the client (400004…) |
51.27 | FBA A par refresh | Refresh | Activates the settings |
20.01 / 22.11 | Ext1 commands / ref1 | Fieldbus A / FB A ref1 | Control and speed from Modbus TCP |
Set up Modbus TCP on the ACS580
8 stepsFit the FENA and cable
Install the FENA-11/-21 in an option slot (0.8 N·m), connect CAT5 or better to X1.
Enable the adapter
50.01 FBA A enable = its slot; 50.02/50.03 = communication-loss action and delay.
Choose Modbus/TCP and the profile
51.02 = 1 MB/TCP ABB E (ABB Drives Enhanced). Use 0 MB/TCP ABB C only for legacy clients.
Set the IP
51.04 = 0 Static IP; 51.05–51.08 address; 51.09 = 24; 51.10–51.13 gateway if needed.
Set the timeout
51.20 = 10 (1 s) and 51.21 = 2 Control RW, so the drive reacts if the client stops sending CW/Ref.
Add extra data (optional)
Groups 53 (client → drive) and 52 (drive → client) add parameters after the fixed CW/Ref and SW/Act registers. Not available with the Classic profile.
Refresh and give control
51.27 = Refresh (drive stopped). 20.01 = Fieldbus A, 22.11 or 28.11 = FB A ref1. Save with 96.07.
Test from the client
Connect to port 502, write 047E then 047F to 400001 and Ref1 to 400002, read 400051 (SW) and 400052 (Act1).
Register map (ABB Drives Enhanced)
| Holding register | Content | Client |
|---|---|---|
400001 | Control word | Write |
400002 | Reference 1 (speed) | Write |
400003 | Reference 2 | Write |
400004 … | Data out 1 … (group 53) | Write |
400051 | Status word | Read |
400052 | Actual value 1 (speed) | Read |
400053 | Actual value 2 | Read |
400054 … | Data in 1 … (group 52) | Read |
Registers are written here in 6-digit form (400001). Some clients use 5-digit form (40001) or zero-based offsets (0 = 400001).
Parameter addressing
Parameter → Modbus register calculator (FENA address modes)
Read or write any drive parameter over Modbus TCP. Enter it as group.index.
Address mode is set in FENA parameter 51.23. Mode 0 is the default and matches legacy 5- and 6-digit Modbus addressing.
Control word and Ref1
Start sequence from the FENA manual: 47Eh (1150) → READY TO SWITCH ON, then 47Fh (1151) → OPERATING.
Control word decoder (ABB Drives profile)
Type a control word in hex, or tap a common value, to see which bits are set.
Ref1 scaling calculator
In the ABB Drives profile, Ref1 = ±20000 equals the drive's scaling value: 46.01 Speed scaling (rpm) in speed control, or 46.02 Frequency scaling (Hz) in frequency control.
Practise Modbus TCP with a real SCADA
Our labs poll ACS580 drives from TIA Portal and a SCADA client over Modbus TCP.
Client side
Siemens S7-1200/1500: use MB_CLIENT with the drive's IP and port 502: MB_MODE 0 to read 400051–400052 and MB_MODE 1 to write 400001–400002, alternating the two requests in a step sequence.
SCADA / HMI: add a Modbus TCP driver, the drive's IP, port 502, and tags for 400051 (SW), 400052 (speed) and any extra data registers.
Function codes: 03 read holding registers, 06 write single register, 16 write multiple registers.
Troubleshooting
| Symptom | Cause | Fix |
|---|---|---|
| Client cannot connect | IP, subnet or cable | Ping the drive; check 51.04–51.09; check the switch port LEDs |
| Connects, drive does not start | Control source or sequence | 20.01 = Fieldbus A; send 047E then 047F |
| Drive trips on comm loss | Client polls slower than 51.20 | Poll faster or raise 51.20 / 50.03 |
| Values in 32-bit registers look swapped | Word order | Match 51.22 to the client (HiLo or LoHi) |
| Changed settings ignored | Adapter not refreshed | 51.27 = Refresh with the drive stopped, or power-cycle |
Modbus TCP has no built-in authentication. Keep drive networks on a separate VLAN behind a firewall, and disable the FENA web pages after commissioning as ABB recommends.
Test yourself: Modbus TCP in ABB VFD
Five quick questions. Answers show straight away.
1. Which 51.02 value selects Modbus/TCP with the ABB Drives Enhanced profile?
2. Where is the status word in the Enhanced map?
3. 51.20 = 10 gives a timeout of:
4. In address mode 0, parameter 01.06 is register:
5. Which TCP port does a client connect to?
Your score: . Want to set this up on a real drive and PLC? Book a free demo class.
Frequently asked questions
Which protocol setting should I use for Modbus TCP on ACS580?
51.02 = 1 MB/TCP ABB E (ABB Drives Enhanced) for new projects. It allows extra data words in groups 52/53. 0 MB/TCP ABB C is for legacy clients.
Which registers carry control and status?
Control word 400001, Ref1 400002, Ref2 400003; status word 400051, Act1 400052, Act2 400053. Extra data starts at 400004 (out) and 400054 (in).
What TCP port does FENA use for Modbus TCP?
The standard Modbus TCP port 502. The drive is the server; the PLC or SCADA is the client.
How does the communication timeout work?
51.20 sets the FENA timeout in 100 ms steps; 51.21 chooses which messages reset it. After it expires, the drive applies 50.02 after the 50.03 delay, so the total reaction time is the sum of both.
How do I read any parameter over Modbus TCP?
In address mode 0, register = 100 × group + index, e.g. 01.06 → 106 (400106). Use the calculator on this page for other modes and 32-bit values.