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# holoscan::HoloscanUcxTransmitter

> HoloscanUcxTransmitter class optionally adds a MessageLabel timestamp to every published message if data flow tracking is enabled.

`HoloscanUcxTransmitter` class optionally adds a [MessageLabel](messagelabel) timestamp to every published message if data flow tracking is enabled.

[Application](application) authors are not expected to use this class directly. It will be automatically configured for output ports specified via [`Operator::setup`](gpuresidentoperator#setup) when [`Application::add_flow`](application#addflow) has been used to make a connection across fragments of a distributed application and data flow tracking has been enabled.

\==Parameters==

See [UcxTransmitter](ucxtransmitter) for parameter descriptions.

```cpp showLineNumbers={false}
#include <holoscan/holoscan_ucx_transmitter.hpp>
```

**Inherits from:** `nvidia::gxf::UcxTransmitter` (public)

***

## Constructors

### HoloscanUcxTransmitter \[#holoscanucxtransmitter]

```cpp showLineNumbers={false}
holoscan::HoloscanUcxTransmitter::HoloscanUcxTransmitter() = default
```

***

## Methods

### publish\_abi \[#publishabi]

```cpp showLineNumbers={false}
gxf_result_t holoscan::HoloscanUcxTransmitter::publish_abi(
    gxf_uid_t uid
)
```

This function overrides the UcxTransmitter::publish\_abi() function.

It first calls annotates the message with a [MessageLabel](messagelabel) timestamp if data flow tracking is enabled. It then calls the base class' publish\_abi() function. Finally, if data flow tracking is enabled, it updates the [Operator](operator)'s number of published messages.

### op \[#op]

#### Overload 1

```cpp showLineNumbers={false}
holoscan::Operator * holoscan::HoloscanUcxTransmitter::op()
```

#### Overload 2

```cpp showLineNumbers={false}
void holoscan::HoloscanUcxTransmitter::op(
    holoscan::Operator *op
)
```

Sets the associated operator for this `HoloscanUcxTransmitter`.

It is set at the

**Parameters**

The operator that this transmitter is attached to.

**See also:**
create\_input\_port() function.

### track \[#track]

```cpp showLineNumbers={false}
void holoscan::HoloscanUcxTransmitter::track()
```

***

## Member variables

| Name        | Type                   | Description                                              |
| ----------- | ---------------------- | -------------------------------------------------------- |
| `op_`       | `holoscan::Operator *` | The operator that this transmitter is attached to.       |
| `tracking_` | `bool`                 | Used to decide whether to use data flow tracking or not. |