Breadcrumb Control System
Sterling Systems & Controls, Inc. customizes each and every project to meet the exacting needs of each customer, such as a breadcrumb control system. Often, that requires a combination of mechanical process equipment and process control/automation equipment and systems. Sterling Systems & Controls has over 50 years of experience and capabilities in mechanical and electrical engineering, process knowledge and automation hardware and programming to be flexible for providing what is needed in each case. In the baking and food industry, there are several major breadcrumbs manufacturers for general and specific use. Our experience in this application area is highlighted here.
The system required included the following primary functions:
- Manual-Off-Auto (MOA) controls for each piece of process equipment.
- Front-end batching and baking automation and controls.
- Back-end grinding, drying and packaging automation and controls.
To accomplish the above, the process control and automation system provides setpoint batching control, coordinates interlocks with downstream equipment, and provides communication, process and equipment monitoring, and alarming for all equipment in the production lines. The equipment provided by Sterling Systems & Controls for this application includes two (2) HMI Control Panels; one (1) installed near the mixing area and one (1) near the dryer/grinder area. The mixer control panel provides the primary operator interface for the batching operation. The dryer/grinder panel provides the primary interface for monitoring the dryer and grinder operation and control. Although each HMI control panel has its own primary purpose, both control panels run the same application program, thereby allowing access to any screen in the entire automation system from either control panel. This provides backup functionality if one (1) HMI control panel goes down.
All process equipment control is via pushbutton control stations located near the individual pieces of equipment or via third-party control systems for the oven and dryer, although this all could have easily been integrated into the Sterling Systems & Controls automation and control system. All communication with existing third-party PLC’s is via EtherNet/IP. There is no database in the control system architecture, and no formulation information is stored. The system is custom-engineered to meet the customer requirement that all batching is to be setpoint-based and requires an operator to type in the specific setpoint values before starting the system.
Bread Crumb Control System – Manual/Off/Auto Control
After a review with the customer, Sterling Systems & Controls, Inc. proposed and provided Manual/Off/Auto equipment control in a clean, easy-to-operate, and modern approach that follows common standards in the industry. All process equipment displayed on HMI control panel screens, which is directly controlled by the Sterling Systems & Controls PLC, contains a Manual/Off/Auto pop-up screen, accessible when the HMI control panel “key switch” is placed in the maintenance mode position. After the maintenance mode is turned on, the authorized user can tap/click on the equipment graphic to pop up the control screen and control the mode of each piece of equipment individually. When the maintenance mode key switch is turned back to the off position, the process equipment will return to the Automatic mode of operation.
In normal operation, all equipment will be in Automatic mode. Equipment is started in this mode by using the physical start/stop button stations (also provided by Sterling Systems & Controls) located near the equipment. When placed into the Off Mode, the equipment will be immediately stopped/closed/de-energized. Any equipment upstream or downstream in Automatic mode would continue to follow all interlocking rules and may stop due to putting a critical piece of equipment into the Off mode.
When placed into the Manual mode, for motors with a dedicated physical start/stop pushbutton, such as the grinder, the motor must still be started by using the physical start/stop buttons while the operator is standing in front of the equipment. However, it will not be interlocked with upstream/downstream equipment. For equipment that does not have a dedicated physical start/stop button, when in Manual mode, the equipment will be started/opened/energized immediately and will not be interlocked with other equipment. All safety-related sensors or switches will always be monitored in both Automatic and Manual modes and cannot be bypassed via the automated control system.
By providing onscreen Manual-Off-Auto control, the system is more in line with industry standards and provides for easier maintenance and troubleshooting of individual pieces of equipment.
Front-End Batching and Baking
The operation’s front-end batching and baking sequence deals with the equipment from the mixer through the divider, rounder, spiral proofer, sheeter, moulder, oven, and spiral cooler to the staling room. When the system is not in maintenance mode and all equipment is in Automatic mode, the general control sequence will be custom-engineered and programmed by Sterling Systems & Controls for the specific customer process objectives and requirements. E-Stops and equipment stops are provided for all equipment and panels. These must be pulled out (stop is off) for the system to operate automatically. In this application, the operator must establish setpoints, speeds, and other settings for the various process equipment and then execute start programs via pushbutton or other manner per the equipment manufacturers’ instruction manual. The system integrates other systems and equipment provided by other manufacturers and system providers, providing overall control of the production process through Sterling Systems & Controls breadcrumb control system.
Back-end Grinding, Drying and Packaging
The operation’s back-end grinding, drying, and packaging sequence deals with the equipment involved with bread staling through the grinder, dryer, other milling, and packaging hopper. When the system is not in maintenance mode, and all equipment is in Automatic mode, the general control sequence will be custom-engineered to meet the specific customer process objectives and requirements. The Sterling Systems & Controls PLC monitors and controls various pieces of equipment throughout these processes. In this specific application, the operator must start or stop items and interface with equipment per the manufacturers instruction manuals. The control system integrates other systems and equipment, providing overall production process control through the Sterling Systems & Controls breadcrumb control system.