Project settings vs System settings

Hi all, it seems everytime I download a program to a PLC or SLC I get this message. "Do you want to change system settings to match project settings" I answer no as I feel the project settings are the ones I want. Does anybody know what this question means, I'm thinking that project settings are things like channel configurations but I'm not sure. Any help would be appreciated.

Ok, so the Project Settings they are referring to includes the name of the RSLinx driver (such as AB_DF1-1 or AB_ETH-1) and the network node number of the SLC/PLC.

Here is the catch though......the project setting just might be the settings the programmer used on his/her computer and those settings are not correct for your computer.

For example, maybe the programmer connected to the processor over an ethernet connection using an RSLinx driver called "My_Ethernet". But on your PC, maybe you are connecting through the serial port using a driver named "AB_DF1-1". So when you go to download, the software notices that you are using a different setting and wants to know if that should become the new Project setting.

The answer should be "Yes". You want that setting updated to match how your computer talks to that SLC/PLC.

OG

Thanx for the input, but.....if the project settings contain my network node then those are the settings I want to keep, otherwise when I download the program the SLC/PLC will not be seen on the network as it may have an old node address. Still somewhat confused.

It's all about the communication driver you are using to download to the PLC and it really depends on the scenario that the program was developed under. Basically the system settings are the comm driver settings for the computer you are currently on and the project settings are the comm driver settings that are saved in the offline copy of the project.

So the settings are different and the software is asking you what to do, use the offline saved settings (project) or use the current system settings.

Say you're an integrator developing logic for a customer. You use your laptop and download to the PLC via the serial port on the front of the PLC, everything's great, project is saved and life is good. Now after startup you copy the program to the customer's laptop but remember that you forgot to tweak some logic, so you use the customer's laptop to connect through the ethernet port because you'd rather do it in a warm office instead of standing outside when it's -20 with a 6 foot serial cable. So when you try to go online you're greeted with the message you describe. Now if the tech that's going to take care of this PLC likes the cold weather then I'd say you don't overwrite the project settings with the system settings and let him use the serial driver but if he likes to vacation in the Carribean then I'd say overwrite the settings with the ethernet driver so he can sit in the office and do a 'go online' from the pulldown menu and not have to worry about the software not being able to find the processor.

It will NOT change the node number of the PLC. It is the node number where your computer expects the PLC to be located. It will NOT change the PLC node number. You are changing the setting for the offline file on your PC only.

The setting where the physical PLC node number is actually set is found in the Communication Channels.

Think of it like printed directions from home to the plant. They work great for me from my home, but if I give them to you then the "path" is incorrect. So you go and lookup the proper directions from your home. Taking a different path doesn't change the location of the plant.

By saying "no" to the message in RSLogix, you keep defaulting to my directions instead of saving your own directions.

OG

Thanx for the info everyone, I understand it now, saying yes or no to this question doesn't affect the program in any way....just how you access it...

Bingo!