This article explains possible reasons why your PLC software may be slow when connecting through the Talk2M VPN to upload, download, or go online with a PLC.
All Ewon Cosy and Flexy models
Why is my PLC software so slow while using remote access?
If you find that your PLC software is slow while using Ewon for remote access, there are a number of factors that could cause this problem. Keep in mind that it could be a multifaceted issue.
Note: Issues like this are quite generic so you must consider all the factors that range from the computer running your software to internet and local network infrastructure then finally the Ewon itself with its connection to the PLC.
Factors to consider:
- The physical distance between you, the Talk2M servers, and the Ewon causes a delay though this should be minimal
- The data rate may be limited by the internet service provider on the eCatcher or Ewon side.
- Network speeds may be limited by the equipment and environment. For example, wireless access points with a weak connection or unshielded cabling near sources of electrical noise.
- Ewons using Wi-Fi or cellular WAN interfaces may have a weak connection
- You may have other devices on the network using network resources through the Ewon or elsewhere causing a bottleneck
- Hardware or virtual machine specifications may directly effect the PLC software's performance
- Some delay may be typical of your PLC software in certain circumstances. For example, uploading/downloading a large program or attempting to view a large amount of live data such as with variable frequency drive parameters.
- The Talk2M VPN may be using UDP or TCP. Generally, the VPN is faster using UDP but TCP is recommended for uploading and downloading PLC programs because it has packet correction. More info can be found here: What is the Difference between UDP and TCP? Choosing the best protocol for the VPN connection.
- There are also known performance limitations with devices from Rockwell Automation. On a local network, it may not be noticeable, but when the traffic is sent through a VPN, there may be a significant amount of delay. With Rockwell devices, we have seen performance issues when the VPN uses UDP and recommend setting it to use TCP.