Port is Closed Error (VX520/V400C)
You may encounter customers getting a 'Port is Closed' error when attempting to use either the VX520 or V400C.
When the 'Process Card' button is pressed in the RecPro checkout a .NET class SerialPort() is used to open the USB COM port. Once opened, it then sends data back and forth with the credit card device and then re-closes the port when the transaction is complete. The 'Port is Closed' message is essentially saying that the port can not be opened when running the 'Serial Port() Open' command. This would indicate that another third party application has taken over the port.
You can monitor the COM port using an application called 'Port Monitor'. Download: https://drive.google.
This program does two things. It allows you to monitor the data flowing through a specified port number. It also allows you to manually 'Open' and 'Close' the port.
When the port is left closed and monitoring is turned on you will see data flowing through COM9 when pressing 'Process Card 1' within RecPro.
If the port is manually opened using the 'Open' button in the port monitor application you can force the 'Port is Closed' message in RecPro. You'll see a 'Status_Access_Denied' in the monitor. Port Monitor took control of the port which is why you now get the error in RecPro. Only one application can take over a COM port at any given time.
More research is needed on this but if you install this monitoring software on the troubled PC you can possibly see what's occupying port 9 by running a scan on that port.
This article also explains how to use an app called 'Process Explorer' to view which applications are using serial ports, if any. This won't always work but it's a good starting point.
https://www.equisys.com/