Medium-Level, Modular Control System for Machine Tools

The BLÚ LT modular system provides real-time process control and monitoring on machine tools of medium complexity in terms of sensor quantity and machine dimensions. In its two formats, the Master Unit can host directly up to either two or four function nodes and is designed to guarantee the maximum level of integration between the measurement system, the machine, and the company network. Derived from the Marposs BLÚ single cable machine networking system, BLÚ LT provides the networkability of BLÚ, but at a more reasonable price point for less complex requirements.

With BLÚ LT, all communication between the master processing unit and the functional nodes is handled by the same protocol and used by the BLÚ single cable system. The proprietary Marposs MMSB bus acquires and transmits the signals in totally digital form, guaranteeing robust, reliable communications.

Featuring the BLÚ Human Interface (HI), specifically designed for communication between the operator and the BLÚ control system, the system is easy to use and fulfills all requirements of the Smart Factory. BLÚ HI dashboards can be displayed in the machine front end PC in their own window or can be easily re-dimensioned to fit within the machine builders' control screens. BLÚ LT can also be supplied with a 7-in. 16:9 color touch screen display for easy programming.

Components of the system are designed to provide mechanical reliability and to withstand dynamic environments and the presence of waste materials produced by the machining process.

BACKGROUND INFORMATION on the original Marposs BLÚ, Single-Cable Machine Networking Solution

The biggest differentiator between BLÚ and existing control networks is that BLU uses a ‘Daisy Chain’ topology, with the appropriate function node located near the specific sensor instead of the common ‘Star’ configuration, which needs a separate cable for each connected device linked back to a central electronic controller. In practice, this means a virtually unlimited number of functional nodes can be connected to a central processing unit using only one cable for a whole BLÚ network.

The savings in installation and maintenance costs for the machine builder and end-user are significant, and upgrades are easily implemented in a ‘plug-and-play mode.’

With a sampling frequency of 45,000 Hz and a 10-nanometer measurement resolution, a BLÚ network fully meets the requirements of contemporary high-precision systems in terms of axis resolution and material removal rates, with ample capacity to accommodate future machine performance enhancements.

The PLC logic management software used in BLÚ networks is designed to minimize the number of I/O signals required. The software also features intuitive menus, a user-friendly programming language, and a fully customizable Human/Machine interface.

The BLÚ hardware is highly modular, with each node being configured for both specific network functions and the environment in which it operates. Processing modules are intended for “Dry” locations like the control cabinet, while functional modules are environmentally sealed to operate in “Wet” locations on and around the actual machine tool.

“Wet” modules feature high-reliability mechanical components designed to operate in the most demanding environments including hot chips, grinding swarf, coolants, vibration, and temperature variations. All BLÚ modules can be located at different distances from each other to simplify installation without impacting network performance.

The BLÚ product offering includes the following nodes:

• Master (Dry)
  • The Processing Node containing basic system software and application programs.
• Measurement (Wet)
  • Quick-Connect support for 2 or 4 LVDT and 2 HBT transducers up to 3 meters away.
• Retraction (Wet)
  • Used with a Measurement Node to actuate pneumatic finger retention on up to 4 measurement heads like the Marposs Unimar.
• WB - Wheel Balancer (Wet)
  • For vibration control in conjunction with ACC vibration sensors and RPM inductive, magnetic or optical rotational speed sensors.
• AE - Acoustic Emission (Wet)
  • Quick-Connect support for 2 Liquid, ring, fixed, internal spindle or rotating sensors.
• HP (Wet)
  • Quick-Connect support for 2 touch probes like the Marposs Mida T25 and high-precision piezoelectric T25P.
• Slide (Wet)
  • Used to operate electro-mechanical slides to move gauges and probes into the grinding area.

A full line of accessories including cables, brackets, joint fasteners, connectors, and plugs are also available for BLÚ networking applications.