Serial port redirection to TCP/IP Telnet


Thread Starter

Darold Woodward

Does anyone know of software that can present an Ethernet connection to an application as a Comm. port? I have a Z-world EM1000 on a device and would like to use that device's software to configure it from my PC. I'd prefer to use my
PC's Ethernet card rather than an external device.

Perhaps what I'm asking for sounds simple, but is actually more complex. Here are the options I have considered:

1. I could put a second EM1000 at my PC and go out the serial port from EM1000 to the other EM1000. This works great, but means that I have to reconfigure the local EM1000 each time I want to connect to another device.

2. TCP/Comm from TALTech can do the job, but I have to go out through a serial port across a cable and back into my PC on a serial port and then out through my Ethernet card.

3. Lantronix Redirector software does not run properly on my laptop. I'm going to test it on a simpler machine, but it seems to be quite finicky about when and where it actually works.

If you folks have other suggestions that you have tried or have heard about, I'd love to hear them.

Darold Woodward PE
SEL Inc.
[email protected]
Just some comments "from Lantronix" and on redirector in general.

"Our" software is - of course - to support "our" products and not Z-World's. As a tech guy, I can point this out & but not make a fuse about it. We don't go too far out of our way to stop you, but be aware that the TCP data stream sent is not raw. The redir adds certain things to the stream and our products are expected to strip/use these out before serial transmission. I'm not at liberty to say what these additions are, but I'm sure you can figure it out. There is a newer "beta" redirector you can try at

A comm port "redirector" is attempting to spoof a hardware serial port in software. We always suggest customers try to use this as an interim solution until they can get a true TCP/IP version of the app. Sometime you can never get a true Ethernet version app, then you have to live with the occasional upsets of a redirector.

The problems with this hardware spoof'n are:
1) Many app - especially in industry - are not well behaved comm-port wise. The instant they try to check hardware directly & by-pass WIN32 calls, the redirector will fail.

2) Few serial apps expect an opened comm port to fail read/write - while with TCP/IP sooner or later your socket WILL close. It may be once an hour or once a year, but it will close. While our latest redirector attempts to reopen the socket fast enough to prevent the app from failing, be aware that some apps may require you to close & restart the app to restore comms (ie: to reopen the comm port). True TCP/IP aware apps should gracefully auto-reconnect when the socket read/write fails.

3) Many apps only support hard coded COM1 to COM4. We cannot redirect an existing port, so on some computers this means only 1 or 2 (or no) available ports.

4) TCP will disturb the timing & some protocols care about this. So while DF1 works well thru redirector, Modbus and GE SNP do NOT.

5) It is yet one more tool to install, document, and restore for system recovery.

Best Regards

Lynn August Linse, Senior Product Application Engineer
15353 Barranca Parkway, Lantronix Inc, Irvine CA 92618
[email protected]
Tel: (949)450-7272 Fax: (949)453-7132