The ability to connect to a PLC remotely (or HMI) and to pull data, access webservers and download programs is increasingly a requirement on industrial automation projects. Remote data access and program maintenance saves travel time to sites and simplifies daily operations. Some of the PLC features that enable this are:
- Webserver on PLC and HMI: Allows data monitoring and some updates to PLC configurations
- WebVisualization: These are customizable user interface pages that are embedded in the PLC. WebVisu is the CODESYS term for these HTML5 pages. Some examples of their usage from YouTube are noted here.
- PLC Programming software remote gateway support: This is the ability for a PLC programming software to connect to remote Ethernet based devices. This could be for program downloads or regular program viewing.
This article will cover the steps for remotely connecting from the SoMachine PLC programming software to a remote M241 PLC. The InHand Networks IG601 cellular gateway device is used as the intermediary. Other examples of intermediary gateway devices may include Netbiter by HMS and eWon ( also by HMS now I believe).
Over the last few years, the criteria I have laid out for these devices have included the means to use them without the manufacturer’s cloud- based connection service. Simultaneously, keeping the option to route more secure connections through the cloud service, only when required, is a plus.
The criteria for the gateway device:
- Ability to setup port forwarding at the gateway device
- Ability to use a VPN connection for secure PLC program downloads
- Ability to support a static IP at the gateway device and allow for the above mentioned VPN connection at the same time.
The InHand Networks IG601 meets these criteria. Getting this set up can be accomplished with two sets of steps. The InHand steps and the SoMachine steps.
InHand Networks Steps:
- Connect to the InHand Device Cloud at http://g.inhandnetworks.com/. For initial setup, follow instructions per the Device Manager configuration video.
- Install Device Touch on the connecting PC. The installer is available in the Device Cloud portal. The next steps will assume proper setup of the Device Cloud and connection using Device Touch on the local PC. Instructions on Device Touch are available at the following link.
NOTE: While in the Device Cloud, be sure to set up a site, a device and the PLC. I forgot to add the ‘Controller’ once. It took some time and a call to InHand’s support team to figure it out.
- Open Device Touch on your computer and connect with your Device Cloud account. Once connected to the cloud. Connect to the specific site/gateway but selecting it and clicking on the ON/OFF slider bar.
- In SoMachine, configure connectivity in the SoMachine gateway. The gateway is accessible by double clicking on the root of the controller directory in the device tree.
5. The connection method is set to IP address. In the example, the remote controller IP address was set to 10.0.0.100 with a subnet mask of 255.255.255.0
6. Per step 3 above, if Device Touch is active and the Maintenance Channel is on/ready (screen cap below), go to the Online menu and select Login.
NOTE: The update key on the gateway will not result in the detection of the controller in the Gateway list. Entering the IP address and selecting ‘Login’ actually triggers the process if searching for the device and placing it in the available controllers list in the Gateway. The Update button in the Gateway may not find remote devices. As such, the remote PLC may not show up even if by clicking on the Update button.
- The gateway will scan the remote network via the Device Touch adapter. Once the controller has been found, it will show up on the controller list in the gateway with a REM icon next to it.
Note: The standard warning message indicating the pending connection to a controller will pop up prior to an actual login. Entering Alt-F will proceed with the connection and potential remote download of a program. Clicking the Cancel button will abort the connection.
Should the remote controller not be detected using the IP address connection method above, restart the SoMachine gateway as shown in the screen cap below. Subsequently repeat step 4 above.
Should questions or comments arise, put it in the comments section below.