---
title: "Action definitons"
slug: "action-definitons"
updated: 2026-06-12T15:45:22Z
published: 2026-06-12T15:45:22Z
canonical: "docs.calculus.group/action-definitons"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.calculus.group/llms.txt
> Use this file to discover all available pages before exploring further.

# Action definitons

Action definitions determine the value and parameters to be sent to a device, and on which path, when an Action button is pressed.

## Adding action definitions to an asset type

Click **Assets** in the navigation menu and open the **Types** tab.

![List of assets including boilers, chillers, and generators in a management interface.](https://cdn.document360.io/94d0a983-5058-4b02-8d06-1228a999a7a1/Images/Documentation/2026-06-04_13-14-20.png?sv=2026-02-06&spr=https&st=2026-11-11T13%3A48%3A37Z&se=2026-11-11T14%3A48%3A37Z&sr=c&sp=r&sig=x540%2FZWrhv%2B38ZpEwhsOg508SflQ4pPmwU3eMomOkV0%3D)

Select the asset type you want to create an action definition for and go to the **Action Definitions** tab. Click the **Add Action Definition** button.

![Editing asset type settings for generators with no data available yet.](https://cdn.document360.io/94d0a983-5058-4b02-8d06-1228a999a7a1/Images/Documentation/2026-06-04_13-15-01.png?sv=2026-02-06&spr=https&st=2026-11-11T13%3A48%3A37Z&se=2026-11-11T14%3A48%3A37Z&sr=c&sp=r&sig=x540%2FZWrhv%2B38ZpEwhsOg508SflQ4pPmwU3eMomOkV0%3D)

A panel appears, where you can set a name for the action definition.

![Form for adding action definitions with fields for name, value, and parameters.](https://cdn.document360.io/94d0a983-5058-4b02-8d06-1228a999a7a1/Images/Documentation/2026-06-04_13-16-34.png?sv=2026-02-06&spr=https&st=2026-11-11T13%3A48%3A37Z&se=2026-11-11T14%3A48%3A37Z&sr=c&sp=r&sig=x540%2FZWrhv%2B38ZpEwhsOg508SflQ4pPmwU3eMomOkV0%3D)

In addition to the name, there are additional fields to fill in:

- **Default Value** The value to send, in case the user does not specify one when the action button is pressed.
- **Maximum Queue Time (Minutes)** The allotted time in minutes for the action to remain queued, after which it is removed from the queue.
- **Path** The gateway (or gateway|slave) path, the action is sent to.
- **Measurement Path** The sensor path the action is sent to (optional).
- **Value Label** A short descriptive text for the value (optional).
- **Value Suffix** A suffix for the value (optional).
- **Value Editable** If enabled, lets the user specify the value for this action. When disabled, the default value is used.
- **Parameters** Optional parameters in JSON format. If no parameters are required, leave this at the default “{}” (an empty JSON object).

Click **Save** to add the action definition.

### Parameters explained

Generic write actions are available for Modbus TCP and Modbus RTU. Each write action uses a specific set of parameters (see the tables below):

| **Parameter Key** | **Parameter Value** |
| --- | --- |
| “StartRegister” | The starting address for the write operation. |
| “Registers” | An array of comma-separated values to be written. |
| “StartBit” | The first bit to write to (starting with 0). |
| “BitLength” | The number of bits that get overwritten. |
| “StartCoil” | The address for the write operation. |

#### Modbus TCP

| **Path** | **Description** | **Parameters** | **Result** |
| --- | --- | --- | --- |
| write | Writes 1 or more holding registers. | { "StartRegister": 100, "Registers": [10, 20, 30] } | Register 100 = 10 Register 101 = 20 Register 102 = 30 |
| { "StartRegister": 100, "Registers": [10] } | Register 100 = 10 |
| writesimple | Writes the Value to exactly 1 holding register. | { "StartRegister": 100 } | Register 100 = Value (or Default Value) |
| writebits | Writes the Value to a given bit range of a single register, without changing the remaining bits. | { "Register": 100, "StartBit": 0, "BitLength": 3 } | Register 100 = First three bits of Value (or Default Value) |
| writecoil | Writes the Value as a boolean to a single coil. A Value of 0 translates to False, any other Value to True. | { "StartCoil": 10 } | Coil 10 = Value (or Default Value) as a Boolean |

#### Modbus RTU

| **Path** | **Description** | **Parameters** | **Result** |
| --- | --- | --- | --- |
| write | Writes 1 or more holding registers. | { "StartRegister": 100, "Registers": [10, 20, 30] } | Register 100 = 10 Register 101 = 20 Register 102 = 30 |
| { "StartRegister": 100, "Registers": [10] } | Register 100 = 10 |
| writesimple | Writes the Value to exactly 1 holding register. | { "StartRegister": 100 } | Register 100 = Value (or Default Value) |
| writesingleregister | Writes the Value to exactly 1 holding register using Modbus FunctionCode 06. | { "StartRegister": 100 } | Register 100 = Value (or Default Value) |
| writecoil | Writes the Value as a boolean to a single coil. A Value of 0 translates to False, any other Value to True. | { "StartCoil": 10 } | Coil 10 = Value (or Default Value) as a Boolean |