GE FANUC PAC8000 Modular I/O

GE FANUC PAC8000 Modular I/O

I/O Modules

I/O modules transfer signals to and from field

instruments. Input modules receive signals

from transmitters and sensors and convert

them into a digital form for presentation to

the BIM or Controller. Output modules receive

commands from the BIM or Controller and

transfer them to actuators. A wide range

of modules is available, including types for

low-level instrumentation, AC mains and

intrinsically safe signals. I/O modules can

have 4. 8. 16. or 32 field channels.

Field terminals

Field terminals provide the interface between

the I/O modules and the field wiring. They

include fusing and loop disconnect as options.

A mechanical keying system helps prevent

an I/O module from being connected to the

wrong type of field terminal. Field terminals

mount onto the module carrier, one to each

I/O module. They are clamped firmly by the

I/O module to form an electrical and mechanical assembly of high integrity. They may be

replaced in service without removing carriers

or disturbing the operation of other modules.

Carriers

Carriers form PAC8000’s physical and electrical backbone by providing a mounting

onto a flat panel or T- or G-section DIN rail.

They support and interconnect the BIM or

Controller, power supplies, I/O modules and

field terminals, and carry the address, data

and power lines of the internal Railbus.

They provide a termination points for the

LAN and field wiring cable screens and can

also distribute bussed field power to the I/O

modules. I/O module carriers are available to

support four or eight I/O modules.

Power supplies

Good power management lies at the heart

of a true distributed I/O system. 8000 power

supplies accept locally available unregulated

power and provide a regulated supply for the

BIM or Controller and I/O modules. Supply

redundancy is supported.

Bus Interface Module (BIM)

The BIM provides a serial data connection

to a host controller, which could be a distributed control system (DCS), a programmable

logic controller (PLC), or a PC running a soft

control package. A choice of BIMs allows you

to accommodate the most popular fieldbus

protocols. The BIM also uses a fast internal

bus to pass data to, and obtain data from,

the I/O modules. Only one BIM is required at

each node to control up to 64 I/O modules.

Controllers

Controllers are an alternative to BIMs - and

are used where distributed control is required,

rather than distributed IO. A number of

different Controllers are available which

are suited to particular applications. The

Logic Controller runs applications based on

IEC61131 languages, the Process Controller

has a control package that uses DCS-style

function blocks and the Hybrid Controller can

run both application packages in a single unit.

The SafetyNet Controller is SIL 2 compliant

for emergency shut-down and fre and gas

applications. The RTU Controller runs IEC61131

application programmes and supports DNP3

communication protocol.

“HART-ability”

The use of ‘smart’ instruments on process

plants is growing but this investment is not

always fully exploited. Whether it is for a new

installation, or the upgrade of an existing

one, we have solutions that provide the

connections between the HART field instruments, the control systems and the asset

management software.

Specifically, the PAC8000 Process I/O system

has been designed to be transparent to

HART signals, thus allowing the host control

software and any HART field instruments to

communicate directly with each other.

In addition, PAC8000’s HART connections

8000 in your system

Figure 1 shows two possible methods for

linking the 8000 into a system. On the left is

a host controller system that uses fieldbus as

the main distribution medium. On the right

is a section of a typical DCS/PLC information network, with an operator station that

uses a separate interface to the process

fieldbus. The number of 8000 nodes that

can be accommodated depends upon the

addressing capability of the fieldbus in use.

Each 8000 node can address 32 I/O modules

which, depending upon the number of channels per module, can provide up to 512 I/O

points at a single node! A node can consist

of a mixture of analog and discrete modules

and this gives maximum flexibility to the

system designer. Where supported by the

fieldbus, full HART pass-through is provided—

the 8000 appears “transparent”, allowing the

host controller to access the HART capabilities of field instruments.

Wide choice of fieldbus options

F8000 supports a number of popular fieldbus

protocols: Modbus® (RTU mode), Profibus–DP,

eDNP3 and Modbus TCP over Ethernet.

Redundancy options

8000 has been designed to increase availability and minimise downtime. Redundant

LAN channels and power supplies can be

specified as options to increase system availability. All Controllers can be used in redundant

configurations, as can the 8507-BI-DP BIM for

Profibus DP remote IO. Possible downtime is

further reduced by ensuring that the system

components using active circuitry can be

removed and replaced quickly and easily. Even

the field terminals can be replaced without

interrupting the operation of adjacent I/O

modules. Carriers have no active circuitry and

are unlikely to need replacement.

System power supplies

The system power supply at an 8000 node

converts the local DC supply to power the

node and can also provide field power for

I/O modules with low-level field circuits.

Where heavy-current or AC mains circuits

are handled by the I/O modules, 8000’s

innovative Buss