Connecting to Logix

note

This driver is optimized for Logix family devices with firmware version 21+, but supports earlier firmware versions with significantly reduced performance.

Connecting to ControlLogix v21

Watch the video

Connect to a Logix 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.

   

2. Click Create Device Connection +.

3. Select Allen-Bradley Logix Driver and click Next.

   

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

   • Name: LGX
   • Hostname: The IP address of the PLC (e.g., 10.20.1.54)

   

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.

Driver Implementation

This driver maps boolean arrays as members of 32-bit DWORDs. For example, a BOOL[64] in the PLC is represented as a DWORD[2] in Ignition.

Below is a table representing how members of a boolean array items are mapped in the PLC, compared to the Logix driver's implementation.

PLC Mapping	Driver Implementation
boolTag[0]	boolTag[0].0
boolTag[31]	boolTag[0].31
boolTag[32]	boolTag[1].0
boolTag[63]	boolTag[1].31

The Logix driver also supports the following data types:

• DT (Date/Time)
• LDT (Date/Time [ns])
• LTIME (LTime [ns])
• TIME (Decimal)
• TIME32 (Time32 [µs])

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	This is the IP address of the ControlLogix Ethernet module (1756-ENET) to route through to connect a ControlLogix processor. EthernetIP protocol on TCP port 44818 (0xAF12) is used to communicate to ControlLogix processors.
Port	TCP port used for communication. The default is 44818.
Local Address	The local address to connect from when establishing a TCP connection. If left blank, then the driver will simply pick an available address.
Timeout	The maximum amount of time to wait, in milliseconds, for responses from the processor.
Connection Path	If specified, the slot number setting is ignored for this connection path to the processor. Be sure to terminate the path with backplane and slot number.

Advanced

Name	Description
Automatic Rebrowse	When enabled, detects new tags and UDT changes and rebrowses automatically.
Identity Request Frequency	Frequency, in milliseconds, to request CIP Identity Object attributes.
CIP Connection Size	Size used in CIP Forward Open requests.
CIP Connection Timeout	Timeout, in milliseconds, for CIP connections and RPI.
Slot Number	The slot in which the processor resides. If not in a rack, use 0.
Max Concurrent Requests	Number of concurrent requests sent to the device. Increasing this may improve throughput but could overwhelm the processor.