Belimo 2-way EPIV V4 Modbus RTU
Combines measuring, controlling, balancing, and shutting flow in one valve unit.
Template for the Belimo EPIV V4 2-way characterised control valve with sensor-operated flow control via Modbus RTU. Reads real-time flow, temperature, glycol concentration, and volume data while allowing setpoint, flow limit, and control mode adjustments from the cloud.
- Protocol
- Modbus RTU
- Connection
- RS485, 38400 baud
- Registers
- 47, read and write
- Brand
- Belimo
- Key readings
- Relative and absolute position · Absolute volumetric flow · Relative flow · Temperature (C/F) · Glycol concentration · Total volume
- Available commands
- Setpoint (%) · Override Control · Vmin/Vmax flow limits · Control Mode
- Compatible models
- EP...R2+BAC
- Last updated
Registers (47)
29 read, 18 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Relative position | % | Read | |||
| Absolute position | °C | Read | |||
| Relative flow | % | Read | |||
| Absolute volumetric flow in selected unit | l/h | Read | |||
| Analog Setpoint | V | Read | |||
| T_C | °C | Read | |||
| T_F | °F | Read | |||
| Glycol concentration | % | Read | |||
| Series Number 1st part | Read | ||||
| Series Number 2nd part | Read | ||||
| Series Number 4th part | Read | ||||
| Firmware version | Read | ||||
| Malfunction and Service Information | Read | ||||
| Absolute volumetric flow in liter per second | l/s | Read | |||
| Absolute volumetric flow in gpm | gpm | Read | |||
| Setpoint absolute flow in selected unit | l/h | Read | |||
| Nominal volumetric flow in selected unit | l/h | Read | |||
| Nominal volumetric flow in liter per second | l/s | Read | |||
| Nominal volumetric flow in gpm | gpm | Read | |||
| Sensor Value 1 | mV | Read | |||
| Setpoint absolute flow in liter per second | l/s | Read | |||
| Setpoint absolute flow in gpm | gpm | Read | |||
| Total volume in cubic meter | m³ | Read | |||
| Total volume in gallon | gal | Read | |||
| Total volume in selected unit | l/h | Read | |||
| Bus Termination | Read | ||||
| Meter Serial Number First Part | Read | ||||
| Meter Serial Number Second Part | Read | ||||
| Device Type | Read | ||||
| Setpoint | % | Write | |||
| Override Control | Write | ||||
| Vmax in percent of Vnom | % | Write | |||
| Control Mode | Write | ||||
| Unit Selection Flow | Write | ||||
| Setpoint Source | Write | ||||
| Absolute Vmax in liter per second | l/s | Write | |||
| Absolute Vmax in gpm | gpm | Write | |||
| Command | Write | ||||
| Communication Watchdog | s | Write | |||
| Vmin in percent of Vnom | % | Write | |||
| Bus Fail Action | Write | ||||
| Sensor 1 Type | Write | ||||
| Absolute Vmin in liter per second | l/s | Write | |||
| Absolute Vmin in gpm | gpm | Write | |||
| Absolute Vmin in selected units | l/h | Write | |||
| Absolute Vmax in selected units | l/h | Write | |||
| Unit Selection Volume | Write |
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If a device is not in the library yet, we build the template for free as soon as we have the register data.
Use cases
- Monitor absolute volumetric flow and supply temperature on a live cloud dashboard to verify hydronic balancing remotely.
- Adjust Vmin and Vmax flow limits from the cloud when system loads change seasonally.
- Create an alert when glycol concentration drops below the required threshold, indicating a potential leak or dilution.
- Log total volume over time to track water consumption per circuit for energy reporting.
- Override the valve setpoint remotely during commissioning to verify correct actuator response without being on site.
- Switch the setpoint source register between analog and bus mode to hand control to the building automation system or the cloud.
Installation
Wire the Belimo EPIV V4 actuator to the ModbusCloud Gateway using a shielded twisted pair cable connected to the RS-485 A, B, and GND terminals.
Set the Modbus RTU baud rate on the EPIV V4 to 38400 and assign a unique slave address using the Belimo Assistant App or the onboard DIP switches.
Configure the same baud rate (38400), parity, and slave address on the corresponding serial port of the ModbusCloud gateway.
Import the Belimo EPIV V4 template from the ModbusCloud library and assign it to the gateway port where the valve is connected.
Set register 118 (setpoint source) to bus mode so that setpoints written from the cloud are accepted by the valve.
Verify communication by checking that live flow, temperature, and position values appear on the ModbusCloud dashboard.
Things to watch for
Why am I reading zero for absolute volumetric flow even though the valve is open?
Absolute volumetric flow at address 9 is a uint32 value spanning two registers. Make sure the template is reading both registers and combining them correctly. Also confirm the byte order matches the Belimo default (big-endian).
My cloud setpoint changes have no effect on the valve position. What is wrong?
Register 118 (setpoint source) is likely still set to analog mode. Write the value for bus setpoint to register 118 so the valve accepts commands over Modbus RTU instead of following the local analog input.
Which baud rate should I use for the EPIV V4?
The default baud rate is 38400. Ensure the ModbusCloud gateway serial port is configured to the same value. Mismatched baud rates will cause communication timeouts.
Does this template work with both BAC and KBAC variants?
Yes. Both variants use the same Modbus register map. The only difference is that KBAC models include an emergency position function on power failure, which does not affect Modbus communication.
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