Emerson PAC8000 Remote I/O Complete Analysis

Emerson PAC8000 Remote I/O Complete Analysis: Distributed Control Solution for Process Industry

Introduction: Remote I/O systems for harsh environments

In the field of process industry automation, reliable connection between on-site equipment and control systems is crucial. Traditional I/O systems often struggle to cope with harsh conditions such as extreme temperature, humidity, corrosive substances, impact, and vibration. Emerson's PAC8000 Remote I/O is a fully modular I/O solution designed to address these challenges. It is not only suitable for conventional industrial environments, but also for safe operation in hazardous areas such as ATEX Zone 1/2, UL HAZLOC C1D1, making it an ideal choice for industries such as petrochemicals, pharmaceuticals, and energy.

This article is based on Emerson's official data manual and comprehensively analyzes the technical characteristics, system architecture, selection points, and application advantages of PAC8000 Remote I/O.

Chapter 1 Product Overview and Core Features

1.1 Modular Carrier System Architecture

The PAC8000 Remote I/O adopts a unique carrier system design. Each I/O module is installed on a standard carrier, which provides bus connections and field wiring terminals. This modular architecture brings many advantages:

Flexible configuration: Different types of I/O modules can be combined according to actual needs

Hot swappable support: modules can be replaced without power outage, minimizing system downtime to the greatest extent possible

Unified Backplane: All modules communicate through the Railbus Backplane, simplifying wiring

Scalability: Connect multiple carriers through extension cables to achieve distributed layout

1.2 Open Bus Interface

The core of PAC8000 is the Bus Interface Module (BIM), which determines the communication protocol between the I/O system and the upper level controller. Users can select the corresponding BIM based on the fieldbus type:

PROFINET: Supports dual copper cable interface (100Mbps)

Modbus TCP: Ethernet bus interface

In the future, it may also support other protocols such as PROFIBUS DP, Modbus RTU, etc

This openness enables the PAC8000 to seamlessly integrate into existing control systems, regardless of the type of master station used.

1.3 Deep integration with PACSystems

The PAC8000 Remote I/O is optimized for working in conjunction with Emerson PACSystems controllers. It can easily connect to RX3i and RSTi EP controllers through PROFINET or Modbus TCP. All configurations can be completed through the unified PAC Machine Edition (PME) software, achieving a single engineering environment from I/O to controller and then to HMI.

Chapter 2 Operating Capability in Adverse Environments and Dangerous Areas

2.1 Environmental Tolerance

The PAC8000 was designed with strict environments as its primary consideration, and its technical specifications far exceed those of ordinary industrial I/O

Environmental parameter tolerance

Working temperature -40 ° C to+70 ° C

Corrosive gas ISA Level G3

Impact 30g

Vibration 5g

This means that PAC8000 can be installed directly on site without the need for expensive protective cabinets, significantly reducing system costs.

2.2 Hazardous Area Certification

PAC8000 is one of the few I/O systems that can simultaneously meet multiple explosion-proof standards:

ATEX Zone 1/UL HAZLOC C1D1: Can be installed in Zone 1 of explosive gas environment, with on-site wiring options of intrinsic safety (Exi) or increased safety (Exe)

ATEX Zone 2/Division 2: Supports live working (hot swappable)

Intrinsically Safe I/O module: can directly connect sensors and actuators in hazardous areas without the need for additional safety barriers

This capability makes PAC8000 an ideal choice for controlling hazardous areas in process industries.

Chapter 3: High Availability and System Redundancy

3.1 PROFINET System Redundancy (PNSR)

PAC8000 supports PROFINET System Redundancy (PNSR), which is an advanced controller redundancy mechanism:

Dual controller synchronization: Two independent controllers (primary/backup) run simultaneously, with synchronized states

Non disturbance switching: When the main controller fails, the backup controller can take over I/O communication in milliseconds without affecting process control

Long distance redundancy: Two controllers can be up to 10 kilometers apart, enhancing the system's resistance to physical damage

3.2 Network redundancy

Dual LAN ports: Both PROFINET and Modbus TCP interfaces support dual Ethernet ports, enabling Media Redundancy Protocol (MRP) or dual network redundancy

Media support: Copper cable or multimode fiber optic (SFP)

3.3 I/O redundancy

Dual I/O modules: Key signals can be configured with dual I/O modules to further improve availability

Chapter 4 Rich I/O Modules and Diagnostic Functions

4.1 I/O module types

PAC8000 provides an extremely rich selection of I/O modules, covering various signal types and channel densities:

Analog I/O

8-channel AI, 4-20mA, with HART (8101-HI-TX)

8-channel AO, 4-20mA, with HART (8102-HO-IP)

8-channel universal AI (4-20mA, thermocouple RTD、 Voltage (8132-AI-UN)

4-channel thermocouple/mV input (8105-TI-TC)

4-channel RTD input (8106-TI-RT)

Digital I/O

8/16/32 channel DI, 24VDC, isolated/non isolated

8-channel DI, 115Vac/230Vac

8-channel DO, 2-60VDC, isolated/non isolated

8-channel DO, 20-250VAC

8-channel configurable DI/DO (8129-IO-DC)

Special function module

Pulse input module

Sequential Event (SOE) Input Module (32 Channels, 8127-DI-SE)

Smoke and heat detector interface (8139-SH-DC)

Safe AI (8-channel, with HART, suitable for SIL applications) (8810-HI-TX)

Intrinsic safety I/O

8-channel AI, 4-20mA, with HART (8201-HI-IS)

8-channel AO, 4-20mA, with HART (8202-HO-IS)

8-channel RTD input (8206-TI-IS)

16 channel DI, switch/proximity detector (8220-DI-IS)

4-channel DO, solenoid valve drive (8215-DO-IS)

4.2 Diagnostic Information

All PAC8000 I/O modules provide comprehensive diagnostic information, including:

channel status

Disconnection detection

Overload/short circuit indication

Module Health Status

Read directly through PME software or network

Chapter 5: Easy Configuration and Troubleshooting

5.1 PAC Machine Edition (PME) Integration

The PAC8000 uses the same engineering software as the PACSystems controller - PAC Machine Edition (PME). This enables users to:

Unified hardware configuration: Configuring controllers, networks, and I/O in one project

Consistent user experience: use the same editor regardless of project size

Simplify HMI development: Share tag database with QuickPanel+HMI to reduce repetitive work

5.2 PROFINET GSDML file support

For PROFINET networks, PAC8000 provides standard GSDML files. Users only need to import files to easily configure the network of I/O devices without the need for complex programming.

Chapter 6: HART Support and Asset Management

6.1 Integrated AMS

The PAC8000 Modbus EBIM is capable of directly transmitting HART data to Emerson's Asset Management System (AMS). This means:

Remote configuration: HART instrument parameters can be set in the control room

Diagnostic access: Real time acquisition of instrument status information (such as sensor faults, electrode contamination, etc.)

Predictive maintenance: Identifying potential issues in advance through status monitoring

6.2 HART Data in Process Control

In addition to asset management, PAC8000 can also use HART data in process control applications. For example:

Regularly poll the status of HART devices

Trigger alarm when state changes

Use secondary variables such as temperature and pressure for control logic

These features help shorten debugging time, reduce maintenance costs, and improve factory availability.

Chapter 7 Quick Overview of Technical Specifications

Parameter specifications

Installation method: DIN rail

Network interface PROFINET (dual RJ45 or dual SFP), Modbus/TCP

Gateway/Bridge HART

Network redundancy MRP, dual LAN

System redundancy PNSR (PROFINET) or Modbus/TCP

I/O redundant dual module

I/O type 24VDC, 115/230VAC input; 2-60VDC, 20-265VAC output; Analog quantity, RTD， thermocouple

Special module pulse testing, pulse input, SOE， Smoke/Heat Detection

Isolation between channels/channel to ground isolation (DI/DO/AI/AO)

Chapter 8 Comparison of I/O Families

PAC8000 is positioned as a high-end solution for harsh environments and intrinsic safety applications within the Emerson I/O product family. Comparison with other series is shown in the table below:

Product Series  PACSystems RSTi PACSystems RSTi-EP VersaPoint VersaMax Modular RSTI-OM PAC8000 PACSystems RX3i

Type Distributed Slicing Distributed Slicing Rack mounted Airborne Distributed Intrinsic Safety/Harsh Environment Rack mounted

network interface  PROFINET, PROFIBUS DP, Modbus/TCP, Modbus/RTU, DeviceNet PROFINET, PROFIBUS DP, Modbus/TCP, Ethernet/IP PROFINET, PROFIBUS DP, Modbus/TCP, DeviceNet PROFINET, PROFIBUS DP, Modbus/TCP, EGD, DeviceNet, GENIUS PROFINET, Modbus TCP, OPC UA, MQTT PROFINET, Modbus/TCP PROFINET, PROFIBUS DP, Modbus/TCP, EGD, CMX

System redundancy  Modbus/TCP, Modbus/RTU, DeviceNet PROFINET, PROFIBUS DP - PNSR, EGD, GENIUS - PNSR, Modbus/TCP PNSR, EGD

Hot swappable or not, yes or not

Environmental protection IP20, -20~60 ° C IP20, -20~55 ° C IP20, 0~60 ° C, optional -40 ° C and three proof paint IP67, -20~60 ° C IP20, -40~70 ° C, three proof paint IP20, -40~70 ° C, three proof paint IP20, 0~60 ° C, optional -40 ° C and three proof paint

certification  UL, UL HazLoc C1D2, CE, ATEX Zone2, TUV/SIL3 UL, UL HazLoc C1D2, CE, ATEX Zone2 UL, UL HazLoc C1D2, CE, ATEX Zone2 UL, UL HazLoc C1D1, CE, ATEX Zone1， Intrinsic Safety UL, UL HazLoc C1D2, CE, ATEX Zone2, Marine UL, UL HazLoc C1D1, CE, ATEX Zone1, Intrinsic Safety, Marine UL, UL HazLoc C1D2, CE, ATEX Zone2, Marine (Partial)

Module size (W x H x D) 12 x 99 x 70mm 11.5 x 120 x 76mm 12 x 120 x 70mm 66.8 x 163.5 x 70mm 65 x 212 x 29.8mm 42 x 110 x 106mm 34 x 145 x 140mm

Typical Applications: Basic Machine Control Machine Control, Light Process Control General Automation Onboard Cabinet, I/O Poor Environment Process Control Complex Machine/Process Control, Motion Control Complex Machine/Process Control, Motion Control

Good diagnostic level, better, best, best, best, best, best

Chapter 9 Selection Guide and Ordering Information

9.1 Bus interface module and carrier

Order number description

8515-BI-PN PROFINET scanner module, dual 100Mbps copper interfaces

8752-CA-NS Universal Node Service Carrier

8522-EB-MT Ethernet bus interface

8755-CA-NS EBIM Carrier

9.2 General I/O modules (partial)

Order number description

8101-HI-TX 8-channel AI, 4-20mA, with HART

8102-HO-IP 8-channel AO with HART, 4-20mA

8103-AI-TX 8-channel AI, 4-20mA

8104-AO-IP 8-channel AO, 4-20mA

8105-TI-TC 4-channel thermocouple/mV input

8106-TI-RT 4-channel RTD input

8109-DI-DC 8-channel DI, 24Vdc isolated, leakage type

8111-DI-AC 8-channel DI, 115Vac isolated, leakage type

8114-DI-AC 8-channel DI, 230Vac non isolated, module powered

8115-DO-DC 8-channel DO, 2-60Vdc non isolated, module powered

8118-DO-AC 8-channel DO, 20-250Vac isolated, passive

8122-DI-DC 16 channel DI, 24Vdc isolated, leakage type

8125-DI-DC 32 channel DI, non isolated, module powered

8127-DI-SE 32 channel SOE module

8129-IO-DC 8-channel configurable DI/DO

8132-AI-UN 8-channel isolated universal AI

8810-HI-TX 8-channel safety AI, 4-20mA, with HART

9.3 Intrinsic safety I/O module

Order number description

8201-HI-IS 8-channel intrinsic safety AI, 4-20mA, with HART

8202-HO-IS 8-channel intrinsically safe AO, 4-20mA, with HART

8204-AO-IS 8-channel intrinsic safety AO, 4-20mA

8205-TI-IS 8-channel intrinsic safety thermocouple/mV input

8206-TI-IS 8-channel intrinsic safety RTD input

8215-DO-IS 4-channel intrinsic safety DO, solenoid valve drive (IIC gas group)

8220-DI-IS 16 channel intrinsic safety DI, switch/proximity detector

9.4 On site terminals and accessories

Universal terminal

8602-FT-ST: Standard Terminal

8604-FT-FU: Fused Terminal

8605-FT-TC: Thermocouple Terminal

8606-FT-RT: RTD terminal

8610-FT-NA: Non arc terminal (Div 2)

Intrinsic safety terminal

8621-FT-IS: Standard Intrinsic Safety Terminal

8622-FT-IS: Intrinsic safety terminal with circuit disconnect (not applicable to 8-channel DI)

8623-FT-IS: Intrinsic safety terminal for 8220-DI-IS

8624-FT-IS: Intrinsic safety terminal with circuit disconnect

other

8618-FT-MT: 16 pin centralized terminal assembly (Div 2)

8619-FT-MT: 44 pin centralized terminal assembly (Div 2)

8632-FT-NI: 32 channel on-site terminal

9.5 I/O Carrier

Order number description

8707-CA-08 8 module carrier

8709-CA-08 8 module carrier with grounding rod

8710-CA-04 Module Carrier

8711-CA-NS Node Service Carrier, Screw Terminal LAN

8712-CA-NS node service carrier, PROFIBUS-DP LAN

8715-CA-BI BIM carrier only (for PROFIBUS and Modbus LAN)

8717-CA-PS as a carrier for 8910-PS-DC

8720-CA-04 Module Intrinsic Safety Carrier

8723-CA-RB Railbus isolator carrier

8724-CA-PS Intrinsic Safety Module Power Carrier

8727-CA-08 Module Intrinsic Safety Carrier

9.6 Expansion Cable

Order number description

8041-CC-35 Carrier Expansion Cable, 0.35m

8042-CC-85 0.85m

8044-CC-20 2.0m

8034-CC-12 intrinsically safe carrier extension cable set, 1.2m

9.7 Power Supply and Accessories

Order number description

8913-PS-AC 5A 12VDC&5A 24VDC AC input power supply

8914-PS-AC 10A 24VDC AC input power supply

8413-FK-DN 8913/4 Power DIN Rail Installation Kit

8414-FK-SU 8913/4 Power Supply Surface Installation Kit