Too many times I've installed PLC software from other vendors, and couldn't get it to communicate serially after trying everything

RSLinx is a serial port-HOG! If you have it running, and a RS232 device installed, it is pretty much impossible to communicate out of the given serial port. You have to shut down the RS232 serial driver in RSLinx.

The RSLinx driver that causes the most trouble is the ancient "1747-PIC/AIC+" driver for Data Highway 485. Because this loads a special serial port driver in place of the Windows driver, you need to remove it from the RSLinx configuration and sometimes even need to reboot before using a different serial port driver.

The 1747-PIC/AIC+ driver is becoming far less common because it requires a built-in serial port. The 1747-UIC USB/DH485 converter uses the much more well-behaved DF1 Full Duplex driver to accomplish the same connectivity.

If you seldom use RSLinx but want to leave a DF1 or other serial driver configured, use the RSLinx Launch Control Panel to switch from running as a Service to running as an Application and un-check the "Always Run as Service" box. Then RSLinx won't start when the PC starts.

I'll have to try that. I was wondering if there was a way to not have it start up as a service in my taskbar.

Of course, as soon as I post that, I tried it and RSLinx started up the next time I rebooted. Hmm. I'll have to go experiment, but my PC takes so long to boot that I won't do it for fun.

Another thing to be aware of in RSLinx is that there's a driver-by-driver Startup option (look for the Startup button when you create a new driver) that you can set the drivers to start up automatically, manually, or only when an application asks for them.

Eddie,

I saw this and realized that I have forgotten how I actually setup my RSLinx. In reviewing my setup I see that I still have RSLinx setup as a service, but setup the service as Manual start instead of automatic. This is achieved in XP by going to control panel/administrative tools/services and looking for the RSLinx service. Upon opening up the service controls, you can set it up to manual.

This really is the best of both worlds. The service doesnt start until you need it, but when you try to hit the communications in the any RSLogix software, Linx is automatically started. You can shut it down afterwards if you set it up for the toolbar (default i think) by right clicking and telling it to shut down. You can also bring up the control panel you mentioned and start/stop it there.

I will have to check out the comm port control stuff on my computer. I really have always had the impression that ANY comm port driver in RSLinx will commandeer the port. I always have computers with onboard comm ports so maybe there is a difference there. In fact we were just doing some tests with a comm port sniffer here and the new RSLinx would not let it "sniff" when the computer was talking to a SLC 5/04 via the comm port. Interestingly, we have an old 95 machine with an older RSLinx version and a 95 version of the sniffer worked fine.

You made a good point about the individual drivers in RSLinx being able to be started/stopped also. I may have several drivers setup for my comm port which I have to start up as needed. I go to the configure drivers section and click on the startup button and usually select manual. You can select on demand which starts the driver when called, but I like to make sure I am in control. Of course most of my other drivers are set to automatic. Of couse there are those strange drivers that dont allow you to configure or stop them. The KFD (Kentucky Fried Driver) for device net drives me crazy. I have to add and delete it every time I need to use it.

One final thing - this wont help you with your reboot for checking out stuff like service changes, but you might want to look into setting your computer up for hibernate mode. I use this almost exclusively now. A snapshot of your system state is saved to the hard drive (takes a fair amount of space) and when you power up, the computer grabs that info instead of going through the full startup sequence. Comes up in about a 10th of the time. You do have to do a regular reboot every once in a while to take care of memory leaks and other Microsoft issues, but generally works great.

Russell