Help with serial port

[markn]

Hi Folks, I recently upgraded the OS on my Gateway laptop from 98SE to Win 2000 so that I could use RSlogix and RSlinx. The problem I am having is that I can't get the serial port to work with the software. I have checked in the Device manager and the port appears to working, I have also disable the Fax serice and Telephony. I have tryed a warm reboot pressing F8 to get into setup to reconfigure or check the settings in setup, but have had no luck there. Any advice would be appreciated.

[Chavak]

You have to configure your driver in RSLinx in order for them to talk to PLC. See if this helps

[markn]

I understand understand and have done the RS driver configuring with a different computer. My question is directed to testing and checking the serial port in Win2000. Or possibly the serial port is not working, I bought the laptop used years ago and have never used the serial port until now.

[KIKO]

Try to disable the port(i.e com1)...then restart the pc ...then enable the port again...then start your auto configuration using the same port.

[naing]

Hi markn, This FAQ will answer your question about checking the serial port. But I think it is the problem due to your RSLinx version. 'Cause I had met the problem before. Some of RSLinx version can't be configured in a virtual machine like "VPC for Windows", and they can't communicate with "USB to RS232" virtual serial port and bla bla bla bla ............. My final solution was reinstallation of WIN98 on another primary partition of HDD and reinstallation of RSLinx and RSLogix as well. ""Don't forget to backup your activation keys"" Cheer to manufacturers!

[TimWilborne]

Can you see the com port under the Device Manager of the System icon in the Control Panel?

[BobLfoot]

If you do see the com port under device manager make sure it is the com port you thought it was. i've seen w2k and xp make a win 98 com1 out to be com3 or com4.

[markn]

Yes, I can see the comm port under Device Manager and when I open properties, Windows reports that it is functioning properly. I was hoping that ther was a way to look at the comm port in the system BIOS during bootup but I am not that experienced with Win2000.

[BobLfoot]

Assuming you have a standard 9 pin serial port you can build a loop back test connector by shorting pin 2 to pin 3 in a Db9 plug. Plug the loop back adapter into the serial port and open hyperterminal and connect to that com port. be sure that the checkbox for echo typed characters locally is not selected. If you port is working what you type will be seen in hyperterminal. I'd advise you to conduct a loop back test and confirm the port works in windows. Edited May 8, 2006 by BobLfoot

[TimWilborne]

Did you verify the com # like Bob said here?

[markn]

Hi guys, thanks for the advise. I'll be picking up a DB9 plug and making a loop back test tonight. I'll let you know what I learn.

[rainofwind]

hi markn i know little about RSlogix and RSlinks. but from the posts you edited above, i think since the OS can detect the serial port, and the property of the serial port are normal. maybe this has nothing to do with hardware. The rest maybe is the setting and the driver. Are you sure the driver is ok? or the setting is normal? hope it can be your hlep. regards rainofwind

[naing]

Yes, rainofwind You are quietly correct. I also think it isn't hardware problem. But, let's wait his reply.

[markn]

Hi naing and others, Thanks again for your help. I made a loopback plug and performed the test with hyperterminal, with no results even after trying different com port numbers. However, I did download the serial port tester software from the website that you mentioned in your post and I found no activety on Com 1 but I did get a response when I tested Com 3 but the string I sent was not receved as a duplicate. So I thought that perhaps I should use Com 3 to communicate with the PLC. Again I am sad to report that it did not work. I must be overlooking something, the driver configuration with RSlinx is fairly simple and straight forward, I have had success using a different computer (Ihad to negotiate with my wife to use hers). Any help would be apreciated.

[Camel]

Did you open the case on the pc to see if anything is blown up??

[rainofwind]

sorry i don't know if the tester you mentioned is ok. for i have performenced a test in my pc with the tester downloaded from the same website. but the result is disappointed. of course i use the default setting and there are no other devices connected to them. but they return no response. and as i know , the com1 and com2 can be used normally. i think you may try to check the property of the com to get more ioformation if there are conflicts between devices. (such as irq etc..) hopt it can be useful... rainofwind Edited May 12, 2006 by rainofwind

[markn]

Hi Guys, Thanks for all your comments, I don't think I want to get into repairing the serial port on this laptop. Is there another way to communicate with the PLC? Can I use a PCMIA card with Ethernet? Thanks Again

[PdL]

The COM3 story sounds like you have an internal modem which is assigned this COM# (this you can verify at the modems properties in the device manager). Sorry to jump in a bit late but better late than never As a last resort you can try the following. - At the device manager, select the COM port and remove it. - Boot the machine. Windows will now detect the COM port as "new hardware" and will install the default drivers with all default settings. You might be asked for the Win2K installation disc so be sure to have it at hand. With this procedure I think you can be sure that all Windows settings and configuration for the ports are OK. About your last question. Sure you can use a TCP/RS232 gateway. I have good experiences with the following two: - Moxa NPort 5110 (about $115 US, fixed brand name, fairly easy configuration, robust case, fixed COM port settings) - Netbiter Serial Server (innovative company, a lot of cool stuff (MODBUS!), price I have to get back on, standard or robust model, configuration is a piece of cake. Assign IP, install driver and done. All serial settings are emulated from the software thats using the COM port in Windows. Fixed settings also possible through user friendly HTML pages. It has a built in Web server.) Such a gateway also brings the advantage of unlimited cable length, and the possibility to acess the PLC over internet if the right port forwarding and router settings are done. Perhaps other users can recommend a specific one to use with A/B. Good luck! Pim

[markn]

Hi Guys, I've done a bit of detective work and have found that the problem I am having with the serial port has to do with the BIOS needing an upgrade after lading Win2000, funny all the tech people at Gateway would'nt tell me this after I asked them. Thanks for all your help, and I'll let you know how the BIOS flash works out.

[naing]

Be careful markn! Sometimes, the "Flash" will destroy your PC. Make sure you actually need to upgrade the BIOS. Please think about others who can use the softs on the old PCs. With best wishes

[panic mode]

check what windows thinks of your port, look under device manager, ports and if it is there, you will see what port number is assigned to it (no guessing port number) and if driver is installed correctly. if you see yellow or red marks over port icon, or no port icon, you just have found your problem. once this is ok check port operation using some sort of terminal emulator and loop back adapter for example. hyperterminal will also tell you what ports are available (it only lists installed ports). if hyperterminal finds your port but complains that port is already used, bingo, time to find out what is causing the trouble. usual culprits are RSLinx (running as service for example) or ActiveSync or your cell-phone sync software etc. personally i would suggest to not use hyper terminal with loopback adapter if you are new to this because you might be confused with what you see if you expect to see data comming back. in such case you might be better off using second port (can be on other PC) as confirmation of succesfull connection but remember that you need so called crossover or nullmodem cable. If you choose no handshaking, simple 2-3, 3-2 and 5-5 cable is all you need (5minutes of soldering). many plc programming cables are suitable for this too (AB cable CP3, Mitsubishi FX232CAB etc.). note that if you are making this cable you will need two DB9 female connectors. you can make this very small with wires only 1-2" long and then extend it using standard serial cable (saves space for times when you need to carry lot's of them). straight and crossover cables are also available in any computer store for few $$$. here I think Sayal sells them for about 5-6 Canadian dollars.

[Ken Roach]

Hopefully a fresh Win2000-compatible BIOS will do the trick for you. For all applications other than the 1747-PIC driver for DH485 networks, I use a either a Keyspan HS-19 USB/RS232 converter or a Quatech PCMCIA type RS-232 port card. I can't emphasize this enough: the Keyspan model 19 is the only 100% troublefree, reliable, compatible USB to serial converter I have used. Every other one worked OK most of the time, but lacked some feature or misbehaved in some other way. Keyspan's HS19 is maybe $40 and is the best value you'll find in serial devices. I have the Quatech dual-port RS232 card to do serial networking analysis because it supports the Frontline Test Equipment data intercept drivers, and gives me troublefree two-port functionality. Windows Device Manager will show you the most important information about your various COM ports. Another tool I use to figure out COM port behavior is SysInternals' program PortMon. http://www.sysinternals.com/utilities/portmon.html Very handy stuff those guys write.

[DanW]

Great recommendation, Ken, for the Keyspan. I don't think I've ever heard such a comprehensive claim for reliable performance as you've made, but given the bad performance of the cheapies, a $40 converter is well worth the cost. The pdf manual for the Keyspan is impressive. The cheapie USB-232 converters have a quick start guide that amounts to "install drivers & start application" and that constitutes their support and/or knowledge base. I'm gonna order a Keyspan. Dan

[markn]

Hello All, I thought I would share with you what I have learned. I formatted the HD and loaded Win98se and Win2000 on seperate partitions. When I boot to Win98, i have afunctioning serial port, not the case with Win2000. So I am going ahead with the BIOS upgrade. Apparently Win2000 doesn't support the older version of the Bios. I would like to thank you all for your responses. Actually I tested the Com port under Win2000 and it now functions fine I am able to use Rslinx to set up communications =+++ Edited May 25, 2006 by markn

[ianbuckley]

Do you guys know of any way to determine which program is hogging the serial port if it is in use? I know that RSLinx usually will not relinquish control of a serial port once it gains control. Unfortunately, there are other programs that do this as well. The PortMon program linked in this thread is pretty neat, but according to the documentation, it needs to be loaded before the program that will interact with the serial port. If the program using the port is loaded as a service, starting PortMon manually at startup is too late. Is there some way (other than trial and error) to know which program or service to shut down? It would be nice to be able to tell customers asking for phone support an easy way to find this out, rather than telling them to look for RSLinx, then start guessing based on what they read back from the list of open services and programs. Thanks, Ian