---
title: "Hour and Event Meters"
---

# Hour and Event Meters

> <IUCard title="Hour and Event Meters" link="https://inductiveuniversity.com/video/hour-and-event-meters/8.3" />
> <br />

**Hour meter** and **Event meter** refer to the **[Value Mode](../item-types/item-types.md#value-mode)** option settings on tags in Transaction Groups. The Value mode drives values that are used to create values that determine how long a value was true. While the selected Value Mode for most transactions is **Direct** however, the **Hour meter** mode accumulates value for the duration of a condition, and the **Event meter** accumulates count in response to the condition.

## Hour Meter
It is common to write to a tag during the time when a tag's value is true. An hour meter simplifies this effort. Hour meters can be meters that accumulate the millisecond, second, minute, hour, or day.

### Count the Duration of a Tag Being True
1. From the Tag Browser, drag a boolean tag into the **Basic OPC/Groups Items** area of a **Standard** Transaction Group.

    ![Count Duration of Tag Being True Step 1](count-duration-of-tag-being-true-step-1.png)

2. From OPC Browser or Tag Browser, drag a memory tag or OPC tag (must be a numeric data type) into the **Basic OPC/Groups Items** portion of the **Standard** Transaction Group.
3. Right-click on the boolean tag in the Transaction Group and select **Edit**. The **Edit group tag** window is displayed.

    ![Count Duration of Tag Being True Step 3](count-duration-of-tag-being-true-step-3.png)

4. In the **Edit group tag** window, for **Value Mode**, select **Hour meter**.
5. In the **Edit group tag** window, for **Target Type**, select **Other tag** from the dropdown menu. In **Target Name** enter the name of the memory tag as the target, and click **OK**.

    ![Count Duration of Tag Being True Step 5](count-duration-of-tag-being-true-step-5.png)

6. In the **Basic OPC/Groups Items** area where the tags are located, go to the **Target Name** column, left-click on each tag to get the dropdown menu, and set the following:
    1. For the boolean tag, select the memory tag from the dropdown which is set previously as the target tag to write the hour meter to.

        ![Count Duration of Tag Being True Step 6a](count-duration-of-tag-being-true-step-6a.png)

    2. For the memory tag, select Read-only from the dropdown.

        ![Count Duration of Tag Being True Step 6b](count-duration-of-tag-being-true-step-6b.png)

7. Click **Enabled** at the top of the page, and do a **File** > **Save** to start the group. 
8. Set the boolean tag to true to the start of the Hour meter.

## Event Meter
Another common scenario is to count the number of times an event occurred, where an event represents a value change to the tag. For instance, the Event meter targeting a boolean tag would count each value change from false to true. Notice that this is different from the Hour meter as it counts the amount the value changes from false to true, instead of the duration the tag value is true. This count will total the number of cycles the boolean tag has experienced. 

:::note
The data type must be set to integer when using an Event meter regardless of the OPC Item type.
:::

### Count in Response to a Tag Being True
1. From OPC Browser or Tag Browser, drag a boolean tag into the **Basic OPC/Groups Items** area of a **Standard** Transaction Group.
2. From OPC Browser or Tag Browser, drag a memory tag or OPC tag into the **Basic OPC/Groups Items** portion of the **Standard** Transaction Group.

    ![Count in Response to a Tag Being True Step 2](count-in-response-to-a-tag-being-true-step-2.png)

3. Right-click on the boolean tag in the Transaction Group and select **Edit**.
4. In the **Edit group tag** window, set the following:
    * Value Mode: **Event meter**
    * Target Type: **Other Tag**
    * Target Name: **\_Sim_New_Programmable\_/Events** (or name of the tag you are using)
5. Click **OK**.

    ![Count in Response to a Tag Being True Step 5](count-in-response-to-a-tag-being-true-step-5.png)

6. In the **Basic OPC/Groups Items** area where the Tags are located, go to the **Target Name** column. Left-click on each tag to get the dropdown menu, and set the following:
    1. For the boolean tag, select the memory tag from the dropdown which is set previously as the target tag to write the hour meter to.
    2. For the memory tag, select Read-only from the dropdown.

        ![Count in Response to a Tag Being True Step 6b](count-in-response-to-a-tag-being-true-step-6b.png)

7. Click **Enabled** at the top of the page, and do a **File** > **Save All** to start the group. 
8. Set the boolean tag to true to start the Event meter. You'll see the Event Tag update in the Tag Browser.

## Reset an Hour or Event Meter Based on a Condition

You can set the hour or event meter based on a condition.
1. In the Basic OPC/Group Items section, right-click and Edit a Tag that is serving as the Hour or Event meter. The Edit group tag window is displayed.
2. In the **Value Mode** area, select the **Reset on condition** check box.
3. Click the **Tag** icon to display the **Choose Tag** window, and select a Group Tag from the popup window.
4. Click **OK**.

    ![Reset an Hour or Event Meter Based on a Condition Step 4](reset-an-hour-or-event-meter-based-on-a-condition-step-4.png)

5. Next to the **Tag** icon, choose the **operator** sign (for example >), and enter a number. In the example we entered **9**.

    ![Reset an Hour or Event Meter Based on a Condition Step 5](reset-an-hour-or-event-meter-based-on-a-condition-step-5.png)

6. Click **OK**. The target tag will now reset in response to the condition (after nine occurrences in our example).