---
alias: user-guide-automation-task-mes-materialtrackinreply
tags:
- automation tasks
description: "Action task that sends the reply back to a pending Material Track In request received from the MES"
---

# Send Material Track In Reply

:iot-system-reply-lg:

This **action** task sends the reply back to a Material Track In request received from the MES, completing the request/reply exchange started by the [On Material Track In Request](task_material_track_in_request.md) task.

It belongs to the `System / MES` category, under `Actions`, and is available in Data Flow workflows.

![Send Material Track In Reply - Data Flow Task](./images/send_material_track_in_reply_task.png)

## Details

| Fields            | Details                                                                            |
| ----------------- | ---------------------------------------------------------------------------------- |
| Scope             | Connect IoT <br> Data Platform <br> Enterprise Integration <br> Factory Automation |
| Workflow          | Data flow                                                                          |
| `IsProtocol` flag | :material-close:{style="color:#EF5350"}                                       |

## Behavior

When activated, this task sends the reply back to the Material Track In request that the [On Material Track In Request](task_material_track_in_request.md) task is waiting on, which unblocks the MES. The reply comes from the `reply` input, or from the `Default Reply` setting when no reply is provided.

This task must run in the same workflow branch (`zone`) as the request it answers. If there is no pending request to answer, the task emits `Error` instead.

## Inputs

| Name     | Data Type | Description                                                                                        |
| -------- | --------- | -------------------------------------------------------------------------------------------------- |
| reply    | `Object`  | Reply to send back to the Material Track In request. Optional; when omitted, the `Default Reply` is used.       |
| Activate | `Any`     | Activates the task, sending the reply.                                                              |

Table: Send Material Track In Reply task inputs

## Outputs

| Name    | Data Type | Description                                                                        |
| ------- | --------- | ---------------------------------------------------------------------------------- |
| Success | `Boolean` | Triggered when the reply is sent successfully.                                     |
| Error   | `Error`   | Triggered when sending fails, or no pending request exists in the current context. |

Table: Send Material Track In Reply task outputs

## Settings

On the `General` tab, you have the usual settings and the following settings:

| Name          | Data Type | Values | Default | Description                                                                                              |
| ------------- | --------- | ------ | ------- | -------------------------------------------------------------------------------------------------------- |
| Default Reply | `Object`  |        | `{}`    | Optional default message to reply with when the task is activated and no reply is provided on the input. |

Table: Send Material Track In Reply task settings

![Settings Wizard for Send Material Track In Reply Task](./images/send_material_track_in_reply_task_settings.png)

## Remarks

This task pairs with the [On Material Track In Request](task_material_track_in_request.md) task, which listens for the request that this task replies to. It must be executed within the `zone` created by that task.

MES confirms the operation with any reply and does not read its content. To refuse the operation with a reason, link an `Error` with a message into `reply`: MES fails the operation with that message. See [[tutorials-connectiot-mes-interop-scenarios#what-mes-sends-and-expects]].

This task uses a specific structure of context-based data called `zone`. More information on this topic can be read in the [Zones](../zones.md) page.