---
title: "Connecting to PLC5"
---

# Connecting to PLC5

> :::note
> This driver supports PLC-5 processors using either Ethernet/IP or CSP over TCP/IP.
> :::

## Connect to a PLC-5 Device

This driver requires the OPC UA module to be installed and enabled. If the module is missing or disabled, the device will fault with a “Missing Dependency” error on the **Platform** **System** > **Modules** page.

1. On the Gateway, go to **Connections** > **Devices** > **Connections**.

    ![](../../devices-connections.png)

2. Click **Create Device Connection +**.

3. Select **Allen-Bradley PLC5** and click **Next**.

    ![](select-plc5.png)

4. On the **Configure Device** screen, enter the required fields:

   * **Name**: PLC5  
   * **Hostname**: The IP address of the PLC5 (e.g., 10.20.4.56)

   ![](plc5-settings.png)

5. Click **Create Device Connection**.

The device will be listed now on the Connections page. The status will initially show Disconnected, but will move to a Connected state.

![](plc5-connected.png)

## Device Connection Settings

### General

| Name | Description |
|------|-------------|
| Name | A user-defined name for the device. This name appears in OPC item paths and the Devices list. Name must begin with an underscore or a letter, and cannot include special characters. |
| Description | Optional description to help identify the device. |
| Enabled | When selected, the device is active and available for use. |

### Connectivity

| Name | Description |
|------|-------------|
| Hostname | The Hostname value is the IP Address of the PLC-5 processor. The protocol that the PLC-5 processor supports is automatically detected. It will use either CSP protocol on port 2222 (0x8AE) or EthernetIP protocol on port 44818 (0xAF12). |
| Local Address | The local address to connect from when establishing a TCP connection. If left blank, then the driver will select an available address. |
| Timeout | The maximum amount of time to wait, in milliseconds, for responses from the processor. |
| Connection Path | The Connection Path value is used to define the route of the PLC-5 processor to connect to. [Optional] See [Connection Path Format](#connection-path-format) for more details. |

### Advanced

| Name | Description |
|------|-------------|
| Disable Processor Browse | Disables processor browse setting. |
| Zero TNS Connection | Disables the Zero TNS connection setting. |
| Browse Cache Timeout | The amount of time, in milliseconds, to cache tag structure results read from the device. |

## Connection Path Format

The [Connection Path](ignition-modules/opc-ua/opc-ua-drivers/allen-bradley-ethernet/allen-bradley-connection-paths/allen-bradley-connection-paths.md) is used when routing to a PLC5 via ControlLogix hardware, such as a 1756-DHRIO module. Use the following format:

`1,<DHRIO slot number>,<DHRIO channel>,<DH+ node number>`

* **1**: Instructs the 1756-ENET module to move to the backplane  
* **DHRIO slot number**: Slot of the 1756-DHRIO module (0–16 depending on the chassis size)  
* **DHRIO channel**: Use 2 for Channel A, or 3 for Channel B  
* **DH+ node number**: The node number configured in the PLC-5 (octal, range 00–77)

### Supported PLC5 Connection Methods

* PLC-5 L/20E, L/40E, and L/80E via Ethernet/IP
* Any PLC-5 processor connected over DH+ through a 1756-DHRIO module

:::note
ASCII data types from PLC-5 devices are not supported by the PLC5 driver.
:::