Reading EtherNet/IP Data with ControlCom Edge Server

An EtherNet/IP client connects the Edge Server to an Allen-Bradley or Omron PLC over CIP and reads named tags into platform variables. You configure it from the platform in the device's SDK Configuration editor; the Edge Server picks the configuration up on its next restart.

Prerequisites

The Edge Server must already be onboarded as a ControlCom Gateway. The Edge Server getting started guide covers deployment and onboarding.

Each tag you read needs a variable on the gateway to receive it. Create those first (see Creating a Variable); you select each variable by its Topic Property Path when you add a tag below. The tag editor also has a Create New Variable button if you prefer to create them as you go.

Creating an EtherNet/IP Client

1. Open Devices under System in the sidebar and select the onboarded gateway.
2. Open the Edge Server tab. The SDK Configuration editor opens on its Clients tab.
3. Click Add Client and choose Ethernet/IP in the Add New Client dialog.

The new client opens in a side panel and also appears as a card on the Clients tab; click the card to reopen it later. New clients start disabled.

The client panel has three tabs: Connection, Settings and Tags.

Connection

1. Enter a Client Name.
2. Select the PLC Type: ControlLogix (the default), CompactLogix, MicroLogix, Micro800, Micro850, PLC5, SLC500 or Omron.
3. Enter the IP Address of the PLC, such as 192.168.1.100.
4. Enter the Port. Defaults to 44818, the EtherNet/IP standard.
5. Enter the Slot Number, the backplane slot of the processor module. Use 0 for CompactLogix; for ControlLogix, use the slot the processor sits in.
6. Set the Poll Interval (ms), how often each tag is read. Defaults to 1000.
7. Set the Timeout (seconds), how long to wait for a CIP response before the request is treated as failed. Defaults to 15.
8. Turn on Enabled.

Settings

The Settings tab holds maintenance actions: Remove Client deletes the client from this configuration, Export Variables downloads the tag list as a CSV for bulk editing, and Import Client Variables loads a tag list from a CSV.

Tags

A tag is one value read from the PLC. Click Add Tag, then select the new entry in the list on the left. Sort by Tag Path keeps the list in alphabetical order.

On the General tab:

1. Enter the Tag Path, the symbolic name of the tag in the PLC program, such as Tank_1.Temperature, Motor[3].Speed or Program:MainProgram.Counter. UDT members and array elements are supported.
2. Select the Data Type that matches the PLC tag. Supported CIP types are BOOL; the signed integers SINT, INT, DINT and LINT (8 to 64 bits); the unsigned integers USINT, UINT, UDINT and ULINT; the floats REAL and LREAL; STRING; and the bit fields BYTE, WORD and DWORD.
3. Optionally set a Count to read a contiguous array of the chosen type starting at the tag path.
4. Select the Topic Property Path, which is the variable that receives the value. The tag's platform type (number, boolean or string) follows the selected variable.
5. Optionally select a Write Variable to let the platform write to this tag when a matching command is sent. The default is No Write Allowed.

On the Scaling tab (number tags only), Scale (defaults to 1) multiplies the raw value, Offset (defaults to 0) is added after scaling, and Decimals (defaults to 2) rounds the result.

On the Misc tab, Send if Stale After Milliseconds forces a publish when the value has not changed in that time (defaults to 600000, ten minutes), and Deadband Percentage (defaults to 5, number tags only) suppresses changes smaller than that share of the previous value.

On the Transforms tab you can add Value Transforms that rewrite the value before it is published.

Saving

Click Save Configuration in the editor header, then confirm with Save Configuration in the Save SDK configuration? dialog. The configuration is stored on the platform; the gateway applies it on its next restart.

Deployment

The Edge Server reads its configuration when it starts, so a restart is what puts the new client into service. There are two ways to trigger one.

From the platform, open the gateway's Details tab and click Restart in the Send command panel. The Edge Server restarts and reconnects with the new configuration. Edge Server Management describes the full set of SDK commands.

On the gateway itself, restart the container as described in the Edge Server getting started guide.