General Description
The T640 is in itself a range of controllers. In its simplest form, M006, the controller is supplied with a suite of preconfigured, documented, single and dual loop control structures which only require parameterization. In its most advanced form, M004, it is a multipurpose four loop controller configured for continuous control using a powerful set of function blocks supported by SFC for applications requiring sequential or state dependent control.

The block structured architecture, supported by graphical configuration tools (T500 LINtools), makes complex continuous control strategies easy to develop and maintain. Moreover, LINtools has a powerful Sequential Function Chart editor (SFC/ GRAFCET) based on IEC1131-3 standard which allows integration of sequence control with the continuous control database.

Micro DCS
The power of the T640 makes it a complete, self-contained control system. The 2.5Mbit/sec peer-to-peer communications allows groups of instruments to be interconnected without the need for any other components to co-ordinate their activity. The protocol on the peer-to-peer network and the function block architecture are shared with the other members of Network 6000 making it simple to integrate T640s into larger systems.

Low cost of ownership
The T640 has the DIN panel mounting format, 72 × 144 mm and is sealed to IP65. However, the instrument can be removed from the front of the panel leaving the plant wiring undisturbed.

Inside the T640 a plug-in memory module holds both control strategy and operating software, enabling their rapid transfer to a spare instrument.

The same memory module holds the control options. Upgrading a T640 is merely a question of changing the module.

The front panel layout follows the NAMUR convention minimising the requirement for operator training. Supplementary displays can be used for loop identification or general messaging and an area on the front panel gives an overview of all the control loops.

Component kits are available that include terminating resistors for the peer-to-peer network and burden resistors for 4-20mA inputs. These rugged pre-formed components are designed to mount on the sleeve with the minimum of interference to the connectors and wiring. If the instrument is removed these components stay in place maintaining loop and communications integrity.