A Frequently Asked Question
How do I get data from my PLC?
Getting data from your PLC into Ignition is a two step process:
- Add a device, see Connecting to a Device.
- Add some tags, see Creating Tags.
It requires you to touch both the Ignition Gateway and the Ignition Designer. There are also some limitations as to what kind of devices you can connect to Ignition and these are explained throughout the user manual, however, included below is an overview of what you can expect when it comes to compatibility.
Brief summary of device connection in Ignition
- Ignition can only connect directly to devices over Ethernet.
- Ignition can only connect directly to devices for which there is an Ignition device driver. Included drivers are:
- Allen Bradley - ControlLogix 5500, CompactLogix, MicroLogix 11/1400, PLC-5, SLC 505
- Siemens - S7-300, S7-400, S7-1200
- Modbus - The Modbus driver connects to any ethernet enabled device that uses the Modbus protocol.
- Ignition can connect to third party OPC servers via OPC-UA or OPC-DA (using the OPC-COM module) for devices that do not have a supported driver.
Adding a Device to Ignition
Ignition Supported OPC-UA Device
Most commonly you will be adding a device that is supported by one of the built-in device drivers. The first step is connecting your device to Ignition. This is done through the Ignition Gateway Configuration section under the OPC-UA -> Devices page.
- Click "Add a device..."
- Select the driver for the device you wish to add.
- When adding a device you will notice that there are some common settings that are shared by all devices. You can find an explanation of these settings here: Adding a New Device
- Specify any of the required device specific settings for the device (For example, hostname, etc.)
- Check the status of your device to see if it is connected.
As long as all the device information you entered was correct you should see your device in a "Connected" state. The only exception to this is if you chose to add a Siemens or Modbus device. Since these devices don't support the browsing of Tags, you will have to create and address some Tags in the Ignition Designer before the device will stop cycling from a connected to disconnected state.
If you need to address your Tags for your Siemens or Modbus device, you'll want to read about adding Tags in the Ignition Designer as well as how addressing works for the different protocols. You will have to first add a Tag in the Ignition Designer and then edit the OPC Item Path of the Tag using the appropriate addressing scheme.
Adding Connection to 3rd Party OPC Server via OPC-UA
If your device does not have an Ignition driver, you can use a 3rd party OPC server to connect to your device and then have Ignition connect to the server as a client. If the OPC server talks OPC-UA, you can add a new OPC-UA server connection in the Ignition Gateway. Configuration will be different depending on what OPC server you are using, but the following is an example of a popular solution, connecting to KEPServer via OPC-UA, see Connecting to Kepware OPC-UA.
Adding Connection to 3rd Party OPC-Server via OPC-COM
The following section provides a detailed walk-through on how to connect to an OPC server using the OPC-COM module. If Ignition doesn't have a driver for your device and you don't have an OPC server that talks OPC-UA, you have to connect using the OPC-COM module, see Connecting to OPC Classic (COM).
Tags are how Ignition represents your PLC Tags. You create Tags in the Ignition Designer and then you can use these Tags to store history or display PLC data in your projects.
For the most part, Allen Bradley devices support browsing of Tags in the PLC. There are a few exceptions, like the MicroLogix 1200/1500 for which you have to manually address your Tags. For now, we will focus on creating Tags from devices that support browsing.
- Open the Ignition Designer.
- Drag desired Tags from the OPC Browser to the Tag Browser as described here: Creating Tags (if you don't know what Tag Provider means don't worry, merely drag them into the Tags folder). You should now see some Tags in the Tag Browser that show the current values of the respective Tags in your PLC. Don't stop here. You should read through the related links below so you can learn more about Tags and how they work.
Why am I getting Endpoint errors?
If you are getting an "UaException: status=Bad_TcpEndpointUrlInvalid" error, it is because an OPC UA connection Endpoint can only contain certain characters. Most likely, you have an underscore in the Endpoint Address. See the oracle docs for more information on what exactly can be used in the URI.