View Full Version : Modicon Micro Serial Port workarround

May 2nd, 2002, 04:10 PM
My former Problem: I originally found problems with newer computers and going online with the Modicon Micro via the Serial port. I am running Windows 2k and when I would work online, the connection was very slow. Plus, certain tasks like search and online editing didn't even work.

My Solution: I found this USB serial adapter from Keyspan (www.keyspan.com) part number USA-19QW that has fixed the problem. When I go online with the Modicon Micro now, it is super fast. All my former problems have disappeared. Plus, now I have a free serial port to connect to the HMI.

I don't know how much it costs since I found it in the desk drawer of a former employee that was using it with XP, but I think it is about $60.00.

P.S. If anyone knows what the actual cause of the problem is, or if there is a plain windows work around, that would be cool to know too.

May 2nd, 2002, 04:43 PM
In newer PC's they use ACPI (Advanced Configuration and Power Interface). This new feature allows the system to turn off power to things like the serial port even when you are connected, most devices use power from the PC thru the serial cable. The interruption of power can cause problems and has made some companies reinvent drivers for certain serial port adapters...Allen Bradleys PIC being the most known one.
Technote A9874 (http://domino.automation.rockwell.com/applications/kb/RAKB.nsf/0/310D1DD7CF69924785256AFB005D8953?OpenDocument)

This may not have been your problem but check to see if you have ACPI and look at the AB site, maybe disabling Power Management, infrared etc will make the original com port perform well.

May 3rd, 2002, 12:09 AM
Hmmm, I am super curious to see if this USB serial port will work with a PIC adapter. I have only done Modicon since I started working for the oil fields, I don't know where I am going to find a pic or a 5/02.

May 3rd, 2002, 08:39 AM
I mentioned the AB thing to show how ACPI affects the serial port, thought you might get original com port to act right by following some of the suggestions.

Titin Sumarni
July 11th, 2006, 04:17 AM
Hi I am titin. I have some problem with my program.
I want to connect 2 CPM2A by serial port.
and I see you are online now.
can you help me??