BRX PLC EtherNet/IP Implicit Scanner Manual Setup from AutomationDirect

Ethernet-equipped BRX PLCs from AutomationDirect can have their onboard Ethernet port or their Ethernet POM configured to operate as an EtherNet/IP Scanner to process I/O Messages, also called Implicit Messaging, with up to 32 EtherNet/IP Adapters. I/O Messaging connections to Adapters can be created using EDS files as the source of the required parameters or by manually entering these parameters. If you need to brush up on EtherNet/IP, check out AutomationDirect’s informative video, which is linked in the description below. Let’s take a look at manually setting up a BRX PLC as an EtherNet/IP Scanner. In the Do-More Designer programming environment, open the system Dashboard. Here in the I/O section, click on the EtherNet/IP Scanner. In the menu that pops up, you can select to Enable or Configure the Scanner. If you click “Configure EtherNet/IP Scanner”, it will give you the option to enable the Scanner if it’s not already enabled - saves a second or two. Click “Yes.” Touring the System Configuration window that opens: The center table displays all of the currently configured Adapters. Above that, this checkbox enables/disables the EtherNet/IP Scanner Service. On the right side of the window, we’ll see a menu of controls that allow the user to add and configure Adapters. The top two buttons allow the user to add NEW Adapters. When adding a new Adapter to the BRX project, refer to the Adapter device’s documentation for I/O Messaging connection requirements. Add Blank Adapters opens the EtherNet/IP Adapter Settings window, with all the fields set to their default values and ready for manual configuration. Before we get into this configuration, we’ll point out a parameter you’ll need to consider when establishing your Ethernet/IP network. Data traffic can become an issue in any communication network since the capacity to transfer data is finite. In the Do-More Designer, the level of traffic on the Implicit messaging network is calculated as Comm Load. The amount of data going back and forth on the network and the speed at which the data is being sent will impact the Comm Load, and we’ll look at each of these as we go through the configuration. Back to the Adapter settings window: Assign a device name and enter its IP address. Since the EtherNet/IP encapsulation protocol uses TCP port 44818, Do-more Designer populates this field for you. While the I/O Messaging connection is established on TCP port 44818, the I/O Messaging data is exchanged on UDP port 2222. The Encapsulation Inactivity Timeout field allows the user to specify how long the BRX CPU will wait before closing the TCP connection to the Adapter once the I/O Messaging data exchange has begun. Two things to note here. First, the Adapter may also initiate the closing of the TCP connection once the I/O Messaging exchange has begun. This is quite common. Also, this setting is not required to be enabled. If left disabled, the TCP connection will be maintained during the I/O Messaging exchange unless the Adapter initiates the closing of the connection. Swap byte data if necessary for word array types being communicated back and forth. Check Default Enable if you want the connection to the Adapter to be enabled by default each time the CPU powers up. Now, we get into the heart of this whole thing: the I/O messages containing the data to be exchanged. The BRX CPU, as an EtherNet/IP Scanner, can support up to 8 messages per Adapter. Click Add to define your messages. Keep in mind that each message will add to the aforementioned Comm Load proportionately to its size. Enable the optional Config Data group to send configuration data to the Adapter. This is optional, but some Adapters require a Config Data connection. Be sure to check the Adapter’s documentation to find the designated connection point and other details of a Configuration Data connection. Each defined message will require configuration of its Input (Target to Originator) and Output (Originator to Target) components. The Input / Output terminology can be confusing. Just keep in mind that these designations take the point of view of the Originator—in our case, the Scanner we are setting up. Input comes into the Scanner; Output is sent from the Scanner to the Target, or Adapter. When configuring the T->O connection, select the connection type for the transmission of Input data. Some Adapters can be configured to Multicast their Input data on the network to be shared with multiple consumers or transmit their Input data only to the Originator on a Unicast connection. Some devices only support multicasting of Input data. In situations where the Adapter supports both and multiple devices are consuming this data, it is more efficient to use Multicast. Enter the Connection Point for the Adapter's Input data block. Some Adapter documentation may refer to the Connection Point as the Input Assembly Instance. Enter the size, in bytes, of the Adapter's Input data block. Enter the Requested Packet Interval, or RPI, for the Input connection. The Input RPI value is the rate, in milliseconds, at which the Adapter will produce and transmit the Input data to the Scanner. The RPI does enter into the Comm Load calculation. The faster you are sending messages, the more traffic is going to be generated. Keep that in mind. Local Address selects the beginning of an existing memory location in the CPU where the Input data received by the Scanner is stored. Configuring the Originator to Target connection is very similar to the steps we took to set up the Target to Originator connection. Enter the Connection Point for the Adapter's Output data block. Enter the size, in bytes, of the block. Enter the RPI, again keeping your Comm Load in mind. Local Address selects the memory location in the CPU where the Output data sent by Scanner resides. Many Adapters support 'Input Only' and/or 'Listen Only' connections. These connections allow the Adapter to transmit its Input data to the Scanner. However, there is no Output data sent from the Scanner. Instead, the Scanner uses the Output connection as a 'Heartbeat' connection. If you are configuring an Input Only or Listen Only connection, configure the Target to Originator connection as you normally would. For the Originator to Target connection, enter the Adapter's Heartbeat Connection Point. Refer to the Adapter's documentation for this parameter. Since there is no Output data, the data size is 0 bytes. The RPI will either be 250 milliseconds or match the RPI of the Input connection; whichever value is greater. For both Input and Output messages, the inclusion of the Run/Idle Header is determined by the Adapter. If the Adapter requires the Scanner to include the additional 4-byte Run/Idle header in the transmission, enable the 'Include Run/Idle Status Header' checkbox. If the Adapter includes this heading in its Input message, check the “Include” box here, letting the Scanner know to expect the extra four bytes of data. If either of these selections do not reflect the Adapter’s configuration, a Connection Size Error will result. That covers Scanner configuration, including manual Adapter connection configuration in Do-More Designer. If it seems like a lot, don’t worry—in many cases, you won’t have to work this hard. In the following video, we’ll discuss setting up the Scanner using Electronic Data Sheets, or EDS files pulled in from the Adapter devices, which makes this whole process a breeze. To learn more about BRX PLCs and their capabilities or any of the thousands of other automation products AutomationDirect carries and supports, visit www.automationdirect.com. Click here for more BRX PLC videos. Click here for more EtherNet/IP videos. Be sure to subscribe to AutomationDirect’s YouTube channel to stay notified of new content, by clicking here.