Objectives
To demonstrate the necessary settings allowing CX-Designer users to upload/download from/to an NS HMI remotely (via Internet for example) - using a Virtual Private Network (VPN) connection.
Introduction
When using CX-Programmer to communicate to a remote PLC (via Internet), there is a setting inside the Ethernet Unit which allows the Ethernet card to connect with a device not on its local network. Please see an example of the setting... (from ETN21 card setup)...
So if a request arrives at the ETN21 unit that does not originate on the local network, the ETN21 unit will attempt to communicate to that device.
In the NS, there is no such option.
The NS is only able to communicate to devices that are...
- On the local network and FINS auto allocation is possible. Or
- Is listed in the IP Conversion table.
Because CX-Designer is being used from a remote location (via VPN), then it is unlikely to be able to adhere to option 1), so the only other possibility is to use option 2) - list the CX-Designer PC in the IP address table.
The IP address of the PC on the VPN is usually allocated dynamically when the VPN is created. But how is this IP address made known to the NS - so that the NS has the IP address set as a valid device to communicate with?
The answer is to use the NS web server service to access the system menu and remotely add the PC IP address 'live'.
To explore the benefits of connecting to an NS HMI remotely in a real application, click the link below to access a machine case study in Omron's packaging area.
Initial Actions (NS local)
Steps required to enable CX-Designer to access an NS remotely (via VPN)
Before NS is shipped to site,
- The gateway address must be set (to access networks outside the local one)
- NS FTP/Web function must be enabled (this can only be enabled on real HMI).
Example:-
IP Address table in HMI and PLC for local connection.
Note that in the following examples, even though the subnet is Class C (255.255.255.0) the FINS node numbers are explicitly set because they do not match the last digit of the IP address (i.e. FINS Node 3 maps to 192.168.13.103). In the PLC (FINS node 2 - set on ETN21 rotary switch), the IP address table is set as follows:-
and in the NS (FINS node 3) a similar table of devices that require connection :-
Actions required to gain access remotely (VPN)
After NS installed on site to access remotely the following steps are required.
- Obtain the IP address of PC before & after VPN connection to note VPN IP address
- Use NS web server function to access System Menu and add PC VPN IP address
- Set CX-Designer communication settings to transfer project with NS
Without the VPN connected find the IP address of the PC by using the command 'ipconfig.exe'
In this example the PC local IP address is 192.168.1.35 (via a Wireless Ethernet Adapter). Now connect the PC to the VPN to ascertain the IP address given to the PC by the VPN. Using 'ipconfig.exe' again shows all the IP addresses assigned to the PC.
The example shows that a new IP address has been provided (10.1.0.6). This is the IP address that must be set into the NS as a 'known' device that the NS is able to communicate with.
Now that the VPN IP address is known, it must be set into the remote NS - to make the PC at the other end of the VPN a 'known' device.
Setting a new IP address into the NS at 'runtime'
Using the Web Server functionality of the NS, log onto the NS (via the VPN connection).
Using a web browser, access the NS web server function.
In this example the NS's IP address is 192.168.13.103.
In this example the NS's IP address is 192.168.13.103.
Once logged on, the NS Web Server base page will be shown. Select 'Operation' option, as this will show a button to allow access to the System Menu - where changes can be made to the communication settings
In the example here the image displayed is from the NS application, but note the System Menu at the bottom..
Once System Menu is selected, press 'Comm.' tab to access the Communication settings. Enable the Ethernet and Show table (IP address table) to be able to enter the newly found IP address of the PC (VPN IP) that requires access to download/upload. Note in this example as well as the VPN IP address 10.1.0.6 (as FINS node 6) being added, a few more have been added as the VPN in used in this example may provide differing IP address depending how many users are connected to the VPN.
Press the 'Write' button to store in NS. Once written, the NS will also have to be restarted.
Now the NS has been set with a new IP address (10.1.0.6) and FINS Node (6). This will enable upload/download using CX-Designer.
Actions required in CX-Designer (connected via VPN)
Settings in CX-Designer are now set according to those on the NS/VPN.
Using the example IP addresses and nodes, it is possible to set correct values in CX-Designer.
In example NS Ethernet is set as FINS Network 1, FINS Node 3 and has IP address 192.168.13.103.
The PC Ethernet is set as FINS Network 1, FINS Node 6 and has IP address 10.1.0.6.
The PC Ethernet is set as FINS Network 1, FINS Node 6 and has IP address 10.1.0.6.
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and the Driver tab settings...
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With these settings, it will now be possible to upload/download the application using CX-Designer. Please remember that NS applications can be large (MB rather than KB), therefore it may take some time to upload/download the application according to the network speeds available.
Note - the IP address table set on the NS (via web server) will be overwritten with the IP address table set in CX-Designer application - if the application is downloaded to the NS. Therefore make sure that the correct values are set in the IP address table before downloading. If the IP address table is overwritten and the VPN IP address is no longer set, CX-Designer will no longer be able to communicate - the NS web server will have to be used again.
Summary
The NS is only able to communicate with devices 'known' to it for the FINS upload/download method. This means the IP address (and notional FINS Node) of the PC must be set in the NS (IP Address table) before the NS will recognise the PC.
When using VPN's, the PC IP address is usually allocated automatically (not fixed), making it difficult to use with an NS that must know all devices for upload/download communication. Using the NS web server functionality it is possible to enter a 'new' IP address into the NS's IP Address table to allow CX-Designer communication remotely.
As an aside, if not using a VPN connection - but maybe UDP/IP Port Forwarding techniques over the Internet, it is also possible to access NS's remotely. However instead of the IP address of the PC (provided by the VPN) which should be entered into the NS IP Address table - the user should ascertain the IP address visible to the NS (usually an Internet IP address). Use sites similar to http://www.whatsmyip.org/ to find the IP address for entry into NS IP address table.
