ABB Freelance 800F Process-level automation: Freelance Rack I/O

Process-level automation: Freelance Rack I/O

Rack I/O is installed in conjunction with DCP10 or

DCP0 rack CPUs. Rack CPUs do not have access

to fieldbus I/O or field devices. In connection with the

AC 800F, Rack I/O is used when a rack CPU has

been replaced by the AC 800F, or if SOE functionality

is needed. In addition, I/O cycles are faster with Rack

I/O than with fieldbus. For example, up to 88 binary

signals can be updated within  ms using just one rack.

Intelligent I/o modules

The I/O modules link the controller and the process,

for signal conversion. They receive data from sensors,

detectors, transmitters and other field devices and

issue positioning commands to the process.

They have the following tasks and characteristics:

• Input and conversion of conventional signals and signal levels

• Galvanic isolation between the process and system

• Status LEDs for inputs/outputs

• Externally-powered outputs

• Automatic fault detection, fault signaling and

temperature monitoring

• Sensor and line-break monitoring

• Short-circuit and overload-protected digital outputs

• Digital inputs protected against incorrect polarity

• Potentially isolated analog inputs

• Hot-swap capability

• No switches, jumpers or potentiometers, as all

settings are configured using the software

• Front panel connection of process signals via

screw terminals with keyed blocks, codeable

against incorrect connection

All Freelance Rack I/O modules are intelligent, i.e.

they have their own processors. Users can configure

the scan times of the I/O modules individually for

each module. The fastest scan time is  ms for binary

modules and 10/500 ms for analog modules. In case

of communication errors, the output modules switch

the outputs to configurable safety values. Where

controller redundancy is configured, the second

controller takes over without interruption.

Mechanical design of Rack I/O

The Freelance 800F Rack modules have a mechanical

design similar to that used in programmable logic

controllers. Its front panel connection method makes

it exceptionally easy to assemble and to service, also

allowing it to be mounted on the wall.

Freelance 800F Rack modules are inserted into racks

from the front and secured in position with screws.

Each is contained within a metal enclosure providing

exceptional mechanical ruggedness and electromag

netic immunity.

All casing materials used are simply screwed togeth

er, allowing them to be separated for future recycling.

Last but not least, the Freelance hardware compo

nents have taken environmental protection into ac

count by using a minimal amount of paint. The mod

ules have no jumpers or switches whatsoever on the

printed circuit boards, meaning that the user does

not need to open the cartridges. No potentiometers

have been used either.

The Freelance Rack I/O is designed to operate in

ambient conditions of 0 to 50° C (32 to 122 °F) with

out forced cooling. A temperature sensor within the

cartridge monitors the temperature of the module

and triggers an alarm when the maximum value

permitted is exceeded.

Quality and electromagnetic compatibility

By using a well-shielded metal case for each module

and also installing EMC filters in each incoming and

outgoing lead, measures have been adopted to

comply with EMC standards without the need of

installation in cubicles. As a result, the Freelance

800F hardware meets the binding EMC standards

and bears the CE Mark. The requirements of IEC 801

and the NAMUR industrial standard have also been

fulfilled. A sophisticated test strategy, the installation

of optical inspection systems, and integrated self-test

functions ensure that the modules are highly reliable.