Automatic Filling Machine Plc's - Troubleshooting

Automatic Filling Machine PLC's - Operator Interface - Troubleshooting

While we have discussed some of the possible reasons behind an inconsistent level on an overflow filling machine, we will look at some other general issues that may arise regarding filling machines in general today.  The operator interface for automatic liquid fillers include a number of different settings, times and time delays.  If any of these settings or times are changed or incorrectly entered, undesired outcomes can result.  Below, the general screens found on most automatic fillers are discussed along with some of the common settings found on these screens.


The main screen of most automatic liquid fillers will simply allow access to the other screens, including those discussed below.  Often, however, the Main Screen will also include some simple on and off controls for the packaging system.  The on and off controls may include the filler power conveyor, the pump used on some filling machines, and a fill cycle toggle switch.  Though rarely the case, an operator will always want to check these main screen buttons to ensure they are in the on position in the case of filling machine malfunction.  This occurs at the beginning of production runs when the operator forgets to start up one or more components before beginning the fill cycle.


The set up screen will include several controls for different components of the bottle filler.  Indexing, vision systems and drip trays are some common components found on the screen.  Each component may be disabled or enabled, or set to one of several options.  For example, vision systems may be set to read normally or inverted (read bottles or read empty spaces in most cases).  When a specific component of a filling machine is not working properly, the operator of the packaging line should first check the set up screen in the interface to ensure proper settings.


The manual toggle screen on a bottle filler is used to manually control select components the machine, such as indexing gates, head dives, drip trays and more.  This screen is normally used only on two occasions, during set up and when performing maintenance on the machine.  Each of the settings should be set to auto for the components to function correctly during production runs.  As with the set up screen, when the issue is with one component of a machine, the manual toggle screen should be checked for proper settings.


The pre-set screen will include the duration and delay times noted at the beginning of this article.  Times such as pump duration, entry and exit gate delay and duration, head dive delays and other settings will help to make up the fill cycle and keep fills consistent.  Once production begins, if an operator experiences inconsistent or incorrect fills, if product runs low or if indexing causes repeated problems, there is likely an adjustment needed in the pre-set screen.  Keep in mind that changeover from one bottle to another will require different settings to correctly fill the new bottle.
In most cases, an automatic filler will include a recipe screen, allowing the user to save settings for a particular bottle.  This is a huge time saving tool, shortening set up several times over.  Once the settings are entered for a bottle (normally factory pre-set), the recipe screen can be used to save and recall the settings at the touch of a button.  LPS does suggest, however, that a packager keep a hard copy of all the settings for each bottle run, to protect against PLC failure, power surges or other unexpected events.  Use this hard copy to double check the settings when inconsistent fills or issues with indexing arise.
While other screens exist on different filling machines, the above screens are where a majority of troubleshooting issues will be solved.  Of course, if the solution simply evades the operator of the machine, LPS technicians are always available to assist with troubleshooting.