MLIO – Module for distributed solutions

A control system often acquires data from technologies which are installed not only in the machinery rooms, but across the building as a whole. When designing and installing the system, the aim is to save cabling and installation costs which represent about 30 to 40 % of the complete system. At some sites, it may be useful to use distributed inputs and outputs, for example as in the MLIO I/O module. This module is ready for installation directly at the body of an air handling unit, cable tray or room wall.

The module is as close to the peripherials as possible, and therefore:

• the cabling costs are reduced,
• the control panel dimensions may be reduced as there are no central terminals and I/O modules.

The I/O configuration was designed as optimized against the usual HVAC sites I/O mix so as to minimize total hardware and installation costs. MLIO contains

• 4 universal inputs (passive temperature, resistance, voltage 0..10 V, dry contact)
• 2 relay 230 V / 5 A
• 1 analogue output 0…10 V.

The Modbus address is set

• on a software basis, same as at all other I/O modules, or
• hardwarewise, using rotary and DIP switches.

Hardware addressing makes installation easy – the installers may configure and address modules with no need for software tools, on the other hand, using software addressing the configuration may be changed even on a remote basis, e.g. where the modules are at air heaters under the ceiling.

MLIO is used also for data acquisition at large objects like stores, halls, and archives, where the technology is in a central machimery room, and sensors are distributed at large area.