Do you mean print to a printer? Or displaying to the alarm window? Why would you want to? Ok, lets say for now you have a valid reason. If you only want to poll the Modicon when you know the communication will not fail, set the poll rate field blank. You may instead connect a logical (such as a Pushbutton, TimeOfDay, etc.) to the poll now field. Push the button when you know the poll will not fail. This is explained in greater detail here on this site. Do a search, I?m sure you?ll get some interesting ideas. If it?s printing the alarms to a printer (you want the commfails but not on the printer, but you want all other alarms to be printed) you may want to place the modbus object into it?s own process and then start that process in another instance of lookout.
You have the option of turning alarm printing on or off for each instance. One gotcha in doing this is you can?t share com ports between instances. Hope all this helps in some way.
