Accuenergy Acuvim II

Compatibility

Compatible with EpiSensor Edge over Modbus RTU

Accuenergy documents Modbus RTU on the Acuvim II's built-in RS-485 port and publishes a register map with addresses, function codes, data types, word order and scaling. This is documented compatibility, without a physical Edge test.

Acuvim IIR and IIW meters, panel (D) or DIN-rail (M), on the built-in RS-485 port with channel 1 set to Modbus, using user manual V3.2.16 and the V3 Modbus map version 1.10 as a best-effort starting point. Check the meter's Basic Parameter Mode and Energy Display Mode before scaling values. Read-only monitoring.

Connect it with

• Modbus Interface ZMB-3X From €399 ex VAT Configure
• Gateway ZGW-20 From €899 ex VAT Configure

Models

Specifications

The Acuvim II series measures three-phase and single-phase systems through external current transformers or sensors, with a fourth current input for measured neutral current. Accuenergy sells it as the Acuvim IIR, with data logging, time of use and alarms, and the Acuvim IIW, which adds waveform capture and power quality event logging. Both come as a 96 × 96 mm panel meter with an LCD display (D) or as a DIN-rail transducer without a display (M), which can take a remote display.^1, 3

Order code

Acuvim IIR or IIW, then D (LCD panel meter) or M (DIN-rail without display), current input 5A (5 A/1 A selectable), mV (333 mV and Rogowski coil) or mA (80, 100 or 200 mA), and power supply P1V3 (100 to 415 V AC, 100 to 300 V DC) or P2V3 (20 to 60 V DC). Example: Acuvim IIW-D-5A-P1V3.^1, 3

Voltage inputs

The October 2026 datasheet gives 480 V AC L-N and 828 V AC L-L nominal full scale, 45 to 65 Hz; the September 2026 manual appendix still gives 400 V AC L-N and 690 V AC L-L. Higher voltages need PTs.^1, 3

Current inputs

Four channels: 5 A or 1 A CT secondaries (0 to 10 A metering range), 333 mV, Rogowski coil, or 80, 100 or 200 mA. Every model needs external current transformers or sensors.³

Accuracy

Active energy class 0.1S to IEC 62053-22 and class 0.1 to ANSI C12.20; reactive energy class 0.5S to IEC 62053-24; voltage, current and power 0.1 %.³

RS-485

Half duplex, optically isolated, on terminals 14 (A+), 15 (B-) and 16 (S, shield). Modbus RTU by default or BACnet MS/TP. Address 1 to 247 (default 1), 2400 to 115200 bit/s (default 19200), parity None1 by default (no parity, 1 stop bit), with even, odd or None2 selectable.^1, 2

Bus

Up to 32 devices on one RS-485 bus and 1200 m of shielded twisted pair, AWG22 (0.32 mm²) or heavier. Avoid T branches and ground the shield at one end only.¹

Optional modules

AXM-RS485 (second Modbus RTU port), AXM-WEB2 family and AXM-NET2 (Ethernet protocols including Modbus TCP), AXM-IO1 to AXM-IO4 (digital, relay, analogue, residual current and RTD inputs and outputs).³

Approvals

Measurement IEC 62053-22, ANSI C12.20 and IEC 61557-12; safety IEC 61010-1 and UL 61010-1; CE and RoHS; BTL listed (B-SA) for BACnet. No MID approval is listed.^1, 3

Housing

96 × 96 × 64.3 mm with a 92 × 92 mm panel cut-out, or an ANSI C39.1 4 inch round cut-out; 51 mm deep behind the panel. An optional cover raises the display to IP66 or NEMA 4X.^1, 3

Environment

Operating -25 to +70 °C, storage -40 to +85 °C, 5 to 95 % RH non-condensing. Control power installation category III.³

Interface

Documented measurements and integration boundaries for Acuvim II.

• Addresses are printed in hexadecimal and decimal and are sent as printed: the manual's own frame reads frequency at 4000H by sending 40 00. Read measurements with FC03. The manual lists function codes 01, 02, 03, 05 and 16, not 04.
• Float values are IEEE 754 single precision in two registers, high word first and each word high byte first: the manual's example returns 42480000H for 50.00 Hz. dword values are also high word first (high word × 65536 + low word).
• Frequency at 0x4000; phase voltages V1, V2 and V3 at 0x4002, 0x4004 and 0x4006 with their average at 0x4008; line voltages V12, V23 and V31 at 0x400A, 0x400C and 0x400E with their average at 0x4010: float, hertz and volts.
• Phase currents at 0x4012, 0x4014 and 0x4016, average current at 0x4018 and neutral current at 0x401A: float, amperes.
• Active power per phase at 0x401C, 0x401E and 0x4020 with the total at 0x4022; reactive power at 0x4024 to 0x402A; apparent power at 0x402C to 0x4032: float. The map's relationship is P = Rx / 1000 in kW, so the register holds watts, var or VA.
• In Secondary mode (the default, 0 at 0x101D) multiply voltages by PT1/PT2, currents by CT1/CT2 and powers by both. In Primary mode (1 at 0x101D) the floats are already primary values. The mode affects only Modbus readings, not the display.
• Power factor per phase and total at 0x4034, 0x4036, 0x4038 and 0x403A; voltage and current unbalance at 0x403C and 0x403E (Rx × 100 %); power demand at 0x4042: float.
• Import and export active energy at 0x4048 and 0x404A, import and export reactive energy at 0x404C and 0x404E, total active energy at 0x4050, net active energy at 0x4052 (signed) and apparent energy at 0x4058: 32-bit, high word first. Per-phase energy counters run from 0x4620 to 0x463D.
• Energy scaling follows the Energy Display Mode at 0x1019: in Primary mode (0, the default) kWh = Rx / 10; in Secondary mode (1) or Primary 0.001 kWh mode (2) kWh = Rx / 1000.
• The V3 Modbus map also gives a one-register Int16 copy of the basic measurements from 0x3200 (frequency Rx / 100 Hz, voltage Rx × (PT1/PT2) / 10 V, current Rx × (CT1/CT2) / 1000 A). The float block at 0x4000 is the one both documents describe.
• Identity: a SunSpec common block starts at 0xC350 with the ID 0x53756E53 (SunS), the manufacturer string at 0xC354 (16 registers), the model at 0xC364, the options string (Acuvim IIR/IIW) at 0xC374, the version at 0xC37C and the serial number at 0xC384.
• System settings from 0x0FFD, the clock at 0x103F to 0x1045, alarm and logging settings, and the energy counters themselves accept FC16 writes, and relays accept FC05. Keep all of them out of a monitoring poll.

Setup

1. Identify the meter

   Read the order code on the label: IIR or IIW, D or M, and the current input type. On a panel meter, note the CT and PT ratios from the settings pages S06 to S09; the settings password is 0000 unless the installer changed it.

2. Read the serial and reading-mode settings

   Page S01 shows the Modbus address, S02 the baud rate, S33 the parity and S38 whether channel 1 runs Modbus or BACnet. Page S31 shows whether Modbus readings are Secondary or Primary, and S27 the energy mode. Enter the same serial values in the Edge serial client and leave the meter's settings as they are.

3. Wire the RS-485 pair

   Connect A+ to terminal 14, B- to 15 and the shield to S on 16, A to A and B to B along the bus. Give each meter its own address and add a terminating resistor beside the last meter only if the signal is distorted.

4. Make two reads

   Read the SunSpec ID at 0xC350 for two registers and expect 53 75 6E 53. Then read phase 1 voltage at 0x4002 for two registers and decode it as a float, high word first, as in the worked read below. Compare the result with V1 on the display.

5. Add the points you need

   Add current, power and energy from the same tables, applying the CT and PT ratios if the meter is in Secondary mode and the divisor that matches the energy mode. Keep FC05 and FC16 writes out of the polling configuration.

Common questions

Why does voltage read as a tiny number close to zero?

The client is taking the low word first. The Acuvim II sends floats with the high word first, as in the manual's own example where 42480000H is 50.00 Hz. Set the point to big-endian word order: 43 66 00 00 at 0x4002 is 230.0 V.¹

Why is current far lower than the display shows?

The meter is in Secondary mode, its default, so Modbus floats arrive before the CT and PT ratios. Multiply current by CT1/CT2, voltage by PT1/PT2 and power by both, or have the installer set Basic Parameter Mode (page S31, register 0x101D) to Primary on the meter. The display is not affected by this setting.^1, 2

Should energy be divided by 10 or by 1000?

It depends on the Energy Display Mode at 0x1019 (page S27). In Primary mode, the default, kWh is the register value divided by 10. In Secondary mode or Primary 0.001 kWh mode, divide by 1000. Read 0x1019 once during commissioning and set the scale to match.^1, 2

Can I use FC04?

The manual lists function codes 01, 02, 03, 05 and 16 only, and every measurement table names 03H for reading. Configure the Edge points as holding registers read with FC03.¹

Why does a DIN-rail meter only answer at 9600 bit/s after a restart?

From firmware 6.20, an Acuvim II M meter (DIN rail, no display) fixes channel 1 to Modbus at 9600 bit/s for 60 seconds after each power cycle, so a meter set to BACnet by mistake can be recovered. After that window it uses its configured protocol, baud rate and parity.¹

Can the Acuvim II be used for billing under MID?

Not on the strength of these documents. The datasheet gives revenue-grade class 0.1 to ANSI C12.20 and class 0.1S to IEC 62053-22, but lists no MID approval.³