AB CompactLogix Ethernet Advanced
Review the following information for setting up and configuring the AB CompactLogix Ethernet Advanced driver.
Overview
This driver can be used for better performance. Multiple tags that belong to the same polling cycle can be read in a single request/response.
Notes:
- The maximum-length custom string that the driver can read as a string is 480 characters.
- This driver provides faster performance over other compatible drivers. If you prefer stability over speed, you can use AB CompactLogix Ethernet FreeTag.
The driver implements two modes: Symbolic and CompactLogix.
Symbolic Mode
In Symbolic mode, the driver supports both CompactLogix and ControlLogix connections. This mode makes tag grouping more efficient compared to the standard driver by trying to combine as many tags as possible but not exceeding the maximum transmission unit (MTU) size for both requests and responses. Compared to CompactLogix mode, it performs better when dealing with PLC changes.
CompactLogix Mode
In CompactLogix mode, only CompactLogix connections are possible. The driver uses numeric handles instead of symbolic names. Usually this allows the reading of more tags per single request compared to Symbolic mode, especially if symbolic names are quite long. Compared to Symbolic mode, it performs better overall without taking into account PLC changes.
PLC Changes
The driver does not detect PLC program changes. Structure templates are read once when a connection is established. If the PLC program is changed, you need to restart the connection.
Litmus Edge Compatible Series
Compatibility parameter | Compatible items |
|---|---|
Driver type | Ethernet |
Validated devices/series | When configuring tags for this driver, you must enter the case-sensitive register name exactly as it is defined in the PLC. See the Free Tags section below to learn more. |
To set up and configure this device in Litmus Edge, you will need to do the following:
- Step 1: Set up and Configure the PLC Device
- Step 2: Set up the PLC Device in Litmus Edge DeviceHub
- Step 3: Configure the List of Registers
Step 1: Set up and Configure the PLC Device
If the device is configured for Ethernet access, find its network parameters. Otherwise, use PLC software on your computer to configure the device for Ethernet access.
Step 2: Set up the PLC Device in Litmus Edge DeviceHub
Configure the following parameters when you Connect a DeviceConnect a Device with this driver. Update default values to the specific setup of your device.
Parameter | Value |
|---|---|
Type | Allen-Bradley |
Driver | AB CompactLogix Ethernet Advanced |
Network Address | The device address you defined in Step 1 |
Network Port | 44818 |
Access Mode | Select Symbolic or CompactLogix |
Slot Number | 0 |
Step 3: Configure the List of Registers
When you Add Tags to the connected device, refer to the following tag parameters and available value types.
You can also Search for Pre-defined Device Tags for this device.
Refer to the following additional resources:
Free Tags
This driver doesn't have a list of available register names in the DeviceHub Add Tag form.
To add tags, you must enter the register name exactly as it is defined in the PLC.
Available Value Types
- bool
- byte
- sint
- int
- dint
- real
- dword
- lint
- lreal
- string
Tag Parameters
- Name: Enter the case-sensitive register name exactly as it is defined in the PLC.
- Value Type: Select a data type from the drop-down list.
- Polling Interval: Enter a value in seconds. This determines how often the tag should poll the register for data.
- Tag Name: Enter a name for the tag.
- Description (Optional): Enter a description for the tag.
- Tag Formula: Enter a formula for the tag to process the generated data. Two variables are permitted: value (current tag value) and timestamp (current tag UNIX time in milliseconds). The following math functions are available:
- sin
- cos
- sqrt
- tan
- power: power(x) performs the operation 10^x.
- log: log(x) is the natural logarithm (the logarithm is in base e).
- exp: exp(x) performs the operation e^x.
- Only Publish on Change of Value: Select the checkbox to only publish NATS messages when the value parameter changes to a new value. Change of Value only applies to boolean, numeric (such as int or float), and simple string data types. It does not apply to complex types, such as JSON or array. Poll-once topics will not be affected by Change of Value settings. These topics will still only see a single message.
- Meta Data: Metadata summarizes basic information about data. This feature allows you to define key-value pair data for the device output payload later on. Metadata can then be used to find, use, and reuse particular instances of data.
Note: If you use special characters in meta data key names, the special characters are replaced with underscore characters in the payload. This can cause two key names to be combined into one. For example, configuring the key names a**b and a&&b will cause only one key name to be created (a__b).