SSO
Member
Hello All:
I have run into a peculiarity, or so I think, with the MicroLogix 1500. We use a data acquisition system that receives information on the status of the different equipment on the line from one main PLC. In our case the main PLC is a MicroLogix 1100. All other PLCs report their status to it via messaging, then on up to the acquisition system.
The problem arises when you want make changes to the MicroLogix 1500 logic (this model does not have on line editing). If the program that you are modifying in the 1500 was saved while the machine was in a running state, when you download some strange things happen.
We will make our changes and then download to the 1500 when the line is shutdown for break/lunch. The peculiarity we are seeing is: when you download to the 1500, the processor will want to be switched onto program mode, which is fine. When the download is finished you will see a dialog box stating the download is complete, do you want to go back to run mode. As soon as this box appears, the bits that were previously showing as off from the 1500 will now appear as on meaning that the machine the 1500 is controlling has come into running state, which should be impossible because the processor is in program mode. At this point we were monitoring the bits in question in the 1100 processor. As soon as you click on yes in the dialog box, then it shows that the 1500 controlled machine shuts down.
I know that the explanation is a bit confusing, but if you can get through it has anyone ever sent his before?
Thanks.
I have run into a peculiarity, or so I think, with the MicroLogix 1500. We use a data acquisition system that receives information on the status of the different equipment on the line from one main PLC. In our case the main PLC is a MicroLogix 1100. All other PLCs report their status to it via messaging, then on up to the acquisition system.
The problem arises when you want make changes to the MicroLogix 1500 logic (this model does not have on line editing). If the program that you are modifying in the 1500 was saved while the machine was in a running state, when you download some strange things happen.
We will make our changes and then download to the 1500 when the line is shutdown for break/lunch. The peculiarity we are seeing is: when you download to the 1500, the processor will want to be switched onto program mode, which is fine. When the download is finished you will see a dialog box stating the download is complete, do you want to go back to run mode. As soon as this box appears, the bits that were previously showing as off from the 1500 will now appear as on meaning that the machine the 1500 is controlling has come into running state, which should be impossible because the processor is in program mode. At this point we were monitoring the bits in question in the 1100 processor. As soon as you click on yes in the dialog box, then it shows that the 1500 controlled machine shuts down.
I know that the explanation is a bit confusing, but if you can get through it has anyone ever sent his before?
Thanks.