8811-IO-DC Field Terminals and I/O Modules

Description

SafetyNet Discrete Input/Output Module features:
• 8 inputs – any combination of inputs and outputs
• Certified for use in SIL 2 safety applications
• Non-arcing inputs and outputs
• Output channels rated up to 2A continuous
• Inputs for dry contact switches
• 24Vdc Bussed Field Power required from 8914-PS-AC

LAN Redundancy
Different LAN Redundancy options are available from the different BIMs. PROFINET BIMs support a ring architecture (PROFINET’s “Media Redundancy Protocol”, or MRP), the Ethernet BIM supports redundant, fault tolerant Ethernet and the Modbus RTU BIM can operate two LANs in a number of different ways based on its configuration. The 8507-BI-DP BIM can provide redundant LANs when redundant BIMs are installed.

HART Pass-through
All PAC8000 BIMs are designed to work with HART field instruments when combined with appropriate HARTcapable Analog I/O Modules. This allows remote asset management packages to communicate directly with HART field instruments. The PROFINET BIM due for initial release will have this feature in 2013, and the 8505-BI-MB Modbus BIM requires the use of the 8512-IF-HA HART Interface Module to enable HART pass-through.

HART Acquisition
PAC8000 HART I/O Modules can directly address smart instruments and provide HART process and status information directly to the host. This enables the implementation of a number of advanced techniques such as live re-calibration of the 4-20 mA loop by continually comparing it to the original digitized measurement from the transmitter.

Composition of process control station
The process control station of DCS is a complete computer system, mainly composed of power supply, CPU (central processing unit), network interface, and I/O. The control system needs to establish input and output channels for signals, which is I/O. The I/O in DCS is generally modular, with one or more I/O channels on one I/O module used to connect sensors and actuators (regulating valves). I/O unit: Usually, a process control station consists of several racks, each rack can accommodate a certain number of modules. The rack where the CPU is located is called the CPU unit, and there can only be one CPU unit in the same process station. The other racks that are only used to place I/O modules are the I/O units.

In terms of network
The DCS network is the central nervous system of the entire system, which is a safe and reliable dual redundant high-speed communication network, with better scalability and openness of the system. However, PLC, as it mostly works as an individual, adopts a single network structure when communicating with other PLCs or upper computers, and the network protocol often does not comply with international standards. In terms of network security, PLC does not have good protection measures, so we use dual redundancy of power supply, CPU, and network.

In terms of hardware
All I/O modules in the DCS system are equipped with CPUs, which can achieve quality judgment and scalar transformation of collected and output signals. They can be plugged and unplugged in case of faults and replaced randomly. The PLC module is just a simple electrical conversion unit without an intelligent chip, and after a fault, all corresponding units are paralyzed.

Domestic DCS system
In the mid-1980s, many units and individual technicians wanted to be involved in the development and production of DCS. Due to excessive investment in funds and the large amount of software engineering, it is necessary for software developers, hardware personnel, and engineering personnel to coordinate their work. In addition, the development of DCS is too complex, involving computer technology, communication technology, control technology, and display technology. It is impossible for a few technical personnel to master so much technology, and at the same time, they do not have so much capital investment, and it is impossible to have output in a short period of time. A few technical personnel do not have the strength to support them. Many technicians can only marvel at DCS. Many units, such as the automation departments of several major steel companies, have also withdrawn from the development of DCS due to insufficient funds. The Acheng Relay Factory has been developing DCS since 1984 and has achieved good results. Due to insufficient funds and chaotic management, I reluctantly withdrew from the DCS competition. The products of STD bus are intermediate products of control systems. In the early 1990s, there were many manufacturers, with annual sales reaching several billion yuan in China (comparable to the current domestic DCS sales). Due to the heavy workload of end users, they are also exiting the market.

In the mid-1990s, DCS components, except for functional blocks, were available on the market. If the controller can use a PC motherboard, the DCS network can also use Ethernet. The human-machine interface can be equipped with general monitoring software, such as KingView. The market situation has undergone significant changes compared to the 1980s. Another wave involves the development of DCS, with various brands of DCS coming out one after another, and about a hundred systems being introduced to the market. After careful analysis, they are repeated at a lower level, with a single function and unable to form a scale.