Slow performing a Loopback test via Hyperterminal with RealPort.


You're running a loopback test of a Digi Device/Terminal server serial port which is in use by RealPort.  In order to accomplish this task, you connect a loopback plug to the physical serial port of the Device/Terminal server, then use a terminal emulation program such as Hyperterminal to open the comm port number which Realport created for that physical port.  With loopback plug in place, the characters typed into Hyperterminal window are displaying on the screen, however the response appears to be very slow.


This is a known issue with Hyperterminal.


There are other ways to loopback test the port outside of Hyperterminal, but for any of the following methods to work, you'll first need to close the Hyperterminal session you had going to the Realport comm port.

Once the Realport comm port has been closed, one of the following loopback methods could be used instead:

1. Ignore the "slow response" problem with Hyperterminal over the Realport com port.  As long as the characters echo on your screen, the port is working fine.  Clean data is clean data, regardless of the speed it streams across your screen.  If the data is garbled however, this might indicate an actual issue.

2. Use another terminal emulation program such as TeraTerm, Procomm, etc.. Digi has a simple TTY program available here for Win 3.x or here for WinNT/2k/XP/2k3 that you can use if necessary. 

3. Connect using a TCP socket. This can be done in most versions of Hyperterminal as well, by selecting "Connect Using TCP/IP (WinSock)" instead of choosing a comm port, then entering the IP address of the Digi Device/Terminal server, and 2000 + the port number you want to connect to.

Example:  physical serial port 1 of the Portserver would be TCP socket 2001.

Additional Resources:

How to make an RS-232 loopback plug
Loopback Testing Asynchronous Ports with HyperTerminal Under Microsoft Windows
Basic loopback testing in UNIX
HOW TO: Loopback Test Portserver or Digi One family Device or Terminal Server products through the CLI using Connect

Last updated: Mar 22, 2019

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