> Scantech SSA2 Control System
 


It has been developed for managing very complex configurations. It is designed for multi-sensor applications and for configurable and flexible topology. It is by far the most advanced, powerful, fastest, integrated QCS control system available in the market.

Entirely developed by Scantech, the SSA2 system is built around a microprocessor chain, whose number may be variable, which communicate through an internal deterministic high-speed bus (100Mbits/sec). The IID Microprocessors (IID = Intelligent Interface Device) interface the specific electronic modules of the measurement system and control. A master computer manages the processors network communications with the external world; that is to say with other Scantech equipment or customer computers.


The SSA2 system has been designed around three core functions:


1. The master computer

It is a powerful onboard computer (400MHz), with a large memory capacity and many communication options, and is running under the real time Linux kernel operating system. It is located inside the Scanner electrical cabinet on the drive side.

It performs the following functions:

  • Manages the internal scanner bus.
  • Finalizes the measurement processing, especially when data from both heads is necessary to determine the correct physical quantity or when data from an other scanner or equipment is needed.
  • Manages the communications with the external world through a 100Mbits Ethernet network, three serial links ports, one being specially dedicated to customer communication, and one USB port for maintenance. The scanner can be connected in parallel with any number of other machines, scanners, control systems and user interfaces. This architecture has the unique advantage of providing real redundancy at the user interface level, and also of eliminating any processing or computation related to the manufacturing process and measurement calculations. In other words, with the operator interface off the measurement and control system will continue to pilot the manufacturing line.
  • Communicates through standard protocols such as Modbus, Modbus Ethernet and OPC.
  • Manages a configurable local operator interface mounted on the drive side of the scanner.


2. The Interface microprocessors (IID)

Equipped with a powerful onboard computer (400MHz), and having a large memory capacity too.They are plugged on all the scanner and control system electronic modules.
For example:

  • Numerical acquisition boards for detectors.
  • X-ray sources control boards.
  • Video acquisition for laser sensors.
  • Input and output boards.

They have the following tasks:

  • They fully manage the electronic modules operation, handle the measurement channel acquisitions, computations and local inputs and outputs.
  • They manage the communication with the internal high speed bus.

Similar to the SSA1 system, each electronic module provides 16 analog channels. This allows the main operating parameter to be digitized (Voltages, currents, temperatures…).

They are all sampled at the same frequency as the measurement channels. Therefore the operating parameters can be displayed as profiles the same way as measurements. This integrated oscilloscope is a unique tool, extremely powerful and useful for the maintenance, particularly in case of remote intervention.


3. Internal Communication Bus

It is a high speed (100 Mbits / sec) deterministic bus. Deterministic means that the frame period is fixed and well defined. The timing of each single task is therefore ensured. This bus can support any number of IID interface processors as thus any number of sensors.

The SSA2 architecture allows variable topologies and is very flexible. As for the number of sensors, the number of I/O boards is not limited too. The figure shows an example of a possible configuration. The I/O flexibility makes it very easy to build simple control loops such as line speed control, control of the rate of flow of raw material or coating knife control from any Scantech equipment.
The overall computation power is really impressive as each IID embeds a 400MHz microprocessor.




Drive System

Scantech SSA2 is equipped with a brushless servo-drive with an integrated resolver. This technology combines flexibility, technical performances, and remarkable reliability.
Flexibility, since the drive controller has its own central processing unit which allows it to be easily programmed for specific functions. For example, the measurement heads can be easily programmed for a specific sequence in case of material break. Moreover, the unit constantly checks the internal drive parameters (temperature, currents, torque, etc. ...).
The high performance is ensured by Brushless servo drives designed for 24 hour/ 7 day operation for robotic applications requiring quick dynamic reaction times.


Local Operator interface

SSA2 also supports a local graphical operator interface. The operator can enter commands, check the scanner status, view alarms and even view the profiles measured material. The local interface is extremely useful when scanner(s) are located away from the line control rooms.