SUDT AccessPort is described as 'AccessPort is an advanced serial monitor, simulation and RS232 data analysis tool. Use to log, view, analyse or automate RS232 communication or simply use as an ASCII Terminal for basic serial port communication and RS232 device configuration'. There are four alternatives to SUDT AccessPort for Windows. The best alternative is Eltima Serial Port Monitor. It's not free, so if you're looking for a free alternative, you could try Bill Serial Port Monitor. Other great apps like SUDT AccessPort are Advanced Serial Port Monitor (Paid) and Listen32 (Paid).
Free Software to monitor (bi-directional) Serial Port communication RS232 between two devices, use our free Bill Serial Port Monitor. This software allows you to view, log, analyse the activity of your full duplex serial RS-232 port.
Listen32 tap into RS-232 transmit signals for monitoring bi-directional communications between two devices. Two COM ports are used in the listening device, the receive line of each connected to the transmit line of one of the communicating devices.