How to Configure SourceForge ENIP Explorer as Ethernet/IP Scanner

This guide is to help you configure the SourceForge Ethernet/IP Explorer as a Scanner for either Explicit or Implicit Messaging. This may be useful if you do not yet have an actual PLC or controller from which to establish communication with the Gocator, or you may not have finished coding your console application to which the Gocator will be communicating. 

Regardless of the system hardware, you can very quickly test out Gocator Ethernet/IP communications using this tool that is freely available at:

https://sourceforge.net/projects/enipexplorer/

Terminology

Scanner vs. Adapter

Typically, the device in your control architecture that opens connections (when necessary) and initiates data transfers is called the Ethernet/IP Scanner. The device that provides data is called the Ethernet/IP Adapter. If you are more familiar with Modbus TCP, then this is comparable to the Modbus Master/Client and Modbus Slave/Server relationship. 

Explicit vs. Implicit

Explicit messaging uses the TCP/IP transport layer and "explicitly" defines the memory storage location of the subsequent request on the Scanner side before requesting the information. Implicit messaging requires the establishment of predefined memory locations on the scanner side to which the adapter sends information at predefined intervals. Implicit messaging is sometimes also referred to as I/O Messaging.

Requested Packet Interval

The time-interval at which the Ethernet/IP adapter transmits a known-length Ethernet message or frame to a scanner. 

Messaging Type Selection

The selection between Explicit and Implicit Messaging really comes down to a few factors:

Choose Implicit (I/O) Messaging if...

• you care about minimizing latency between information updates from the scanner i.e. your application is time-sensitive
• you do not require verification of packet transmission and response i.e. some packet loss is acceptable

Choose Explicit Messaging if...

• packet loss is not acceptable
• your application can accommodate a slower response in each message due to the call-and-response nature of explicit messaging and the choice of transport layer
• you require verification (via response) of certain settings

Now that you have selected the type of messaging that you want to use, please reference the tool setup that corresponds below. 

For both options the Gocator must be correctly powered on, the ethernet connector connected to your laptop's ethernet port, and the port communication settings properly configured to communicate with the Gocator (i.e. you can pull the Gocator web GUI up in Google Chrome). I will assume that the IP address of the Gocator is set to the default of 192.168.1.10 with subnet mask 255.255.255.0 and empty default gateway. 

Configuring Gocator sensor as Adapter and ENIP Explorer as Scanner for Implicit Messaging

Gocator Setup

1. Power the Gocator ON
2. Connect the Gocator Ethernet connector to your laptop's ethernet adapter
3. Configure your laptop's Ethernet adapter to communicate with the sensor
4. Launch Google Chrome
5. Verify that you can load the Gocator web GUI by typing in the default IP address to the URL bar
6. Go to the Output page in the web GUI
7. From the Ethernet output type, click the Protocol dropdown and select Ethernet/IP
8. Check the box for Implicit Messaging
9. From the Byte Order dropdown, select Little Endian
10. From the Trigger Override dropdown, select Force Cyclic
11. Save this as a Gocator job configuration

ENIP Explorer Setup

1. Download ENIP Explorer from SourceForge at the link above and install
2. Launch ENIP Explorer
3. If the software does not detect your Ethernet interface, click the Functions menu and select Open Interface
   1. 
4. From the popup window titled Local Interface, click the IP Address dropdown and select the adapter IP address to which the Gocator sensor is connected. Click OK. 
   1. 
5. Click the Functions menu, and select Add Remote Device Manually
   1. 
6. In the Remote Device popup, type in the IP Address of the Gocator and click OK.
   1. 
7. Next, you have to manually add the 3 Implicit Messaging Instances for Input, Output, and Configuration to the Gocator device
   1. Right click Assembly #4 underneath the Gocator object, and select Add Instance from the popup window
      1. 
   2. Type 100. Press OK. You will see an Instance #100 automatically added under Assembly #4.
      1. 
   3. Type 151. Press OK. 
   4. Type 802. Press OK. 
   5. Once you have the 3 instance added to the Assembly, click Cancel to close the Add Instance popup.
8. Click Functions menu, and select Implicit (I/O) Messaging
   1. 
9. The instance configuration screen for Implicit Messaging will popup
   1. 
10. Click and drag the instances from the left-hand panel to the three instance blocks as shown in the image below. The Configuration instance is 151, the Output instance is 100, and the Input instance is 802. 
    1. 
11. To initiate the Scanner to Adapter connection, click the Forward Open button in the bottom right. Your laptop will now receive messages from the Gocator as long as it is connected, and you may monitor that traffic using Wireshark. 

Configuring Gocator sensor as Adapter and ENIP Explorer as Scanner for Explicit Messaging

Gocator Setup

1. Power the Gocator ON
2. Connect the Gocator Ethernet connector to your laptop's ethernet adapter
3. Configure your laptop's Ethernet adapter to communicate with the sensor
4. Launch Google Chrome
5. Verify that you can load the Gocator web GUI by typing in the default IP address to the URL bar
6. Go to the Output page in the web GUI
7. From the Ethernet output type, click the Protocol dropdown and select Ethernet/IP
8. Check the box for Explicit Messaging
9. From the Byte Order dropdown, select Little Endian
10. Save this as a Gocator job configuration

ENIP Explorer Setup

1. Download ENIP Explorer from SourceForge at the link above and install
2. Launch ENIP Explorer
3. If the software does not detect your Ethernet interface, click the Functions menu and select Open Interface
   1. 
4. From the popup window titled Local Interface, click the IP Address dropdown and select the adapter IP address to which the Gocator sensor is connected. Click OK. 
   1. 
5. The software will attempt to verify all ENIP configured and connected devices. The ENIP explorer should add your laptop's adapter and the Gocator as ENIP configured devices
6. Highlight the Gocator device, click the Functions menu, and select Explicit Messaging
   1. 
7. Configure the Explicit Message request using the Protocols section of the manual. The example shown here is attempting to request the Sensor State Assembly
   1. 
   2. 
8. Click Send and the data response will be displayed in the Data section of the Explicit Message configuration as well as in Wireshark if you are monitoring there.