DCP200 Profile Controller & Recorder - Product Manual

Retransmit Output n Scale Minimum

Scales a linear output module in slot n if it has been selected to retransmit the PV or SP. Retransmit Scale Minimum defines the value of the process variable, or setpoint, at which the output will be at its minimum value. E.g. for a 0 to 5V output, it is the PV or SP value corresponding to 0V. If this parameter is set to a value greater than that for Retransmit n Output Scale Maximum, the relationship between the process variable/setpoint value and the retransmission output is reversed so that higher PV/SP values give a lower output level.

Settings = -1999 to 9999

Default value = Scale Range Lower Limit.

Also refer to: Process Variable, Retransmit Output, Retransmit Output n Scale Maximum, Scale Range Lower Limit and Setpoint.

Reset To Defaults

This Configuration sub-menu selection returns all of the instruments settings back to their factory defaults. It should be used with great care, as the action cannot be undone. A reset is followed automatically by the Setup Wizard. Users must use this wizard and/or configuration menus to set all of the parameters to the correct values for the intended application.

Also refer to: Configuration Menu, and Setup Wizard

Reverse Acting Control

Reverse control action is required for applications where the primary control output will be used to force the process variable up towards the setpoint. A typical application is a furnace. When the control action is selected as reverse acting, primary proportional control outputs decrease the correcting variable as the process variable increases within the proportional band, and primary On-Off outputs turn off when the process variable exceeds the setpoint. The control action of a secondary output is always the opposite of the primary output.

Also refer to: Control Action, Control Type, Correcting Variable, Direct Acting Control, On-Off Control and Proportional Control.

RS485

RS485 (also known as EIA-485) is two-wire, half-duplex, multi-drop serial communications connection. RS485 only defines the physical layer electrical specification, not the protocol that is transmitted across it. It uses differential signals (the voltage difference between the wires) to convey data. One polarity indicates a logic 1, the reverse polarity indicates logic 0. The applied voltages can be between +12 V and -7 volts, but the difference of potential must be > 0.2 volts for valid operation. RS485 can span distances up to 1200 metres using inexpensive twisted pair wires. Data speeds can be as high as 35 Mbit/s over 10 m and 100 kbit/s at 1200 m.

It is recommended that the wires be connected as series of point-to-point (multi-dropped) nodes (not in a star or ring format), with 120ohm termination resistors connected across the wires at the two ends of the network. Without termination resistors, reflections of the signals can cause data corruption, and electrical noise sensitivity is increased. The master device should normally provide powered resistors, to bias the wires to known voltages when they are not being driven by any device. Without biasing resistors, the data lines float and noise can be interpreted as data when actually all devices are silent.

Converters between RS485 and other formats are available to allow computers to communicate with remote devices. Repeaters can also be used to extend the distance and/or number of nodes on a network.

Also refer to: Modbus RTU, and Serial Communications

51-52-25-150, Issue 1 – April 2009

Glossary

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Honeywell DCP200 manual Retransmit Output n Scale Minimum, Reverse Acting Control
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DCP200 specifications

The Honeywell DCP200 is an advanced distributed control platform designed to enhance efficiency, reliability, and flexibility in industrial automation. With a robust architecture capable of supporting a wide range of applications, the DCP200 is perfect for sectors including oil and gas, chemical processing, power generation, and manufacturing.

One of the key features of the Honeywell DCP200 is its scalability. It can be easily expanded to accommodate increasing demands, making it suitable for both small operations and large enterprises. This flexibility allows industries to adopt the system gradually, integrating it into their existing processes without substantial downtime or a steep learning curve.

The DCP200 is built on open standards, facilitating seamless integration with third-party systems and equipment. This compatibility ensures that companies can leverage existing infrastructures and investments, fostering a more cohesive operational environment. Enhanced interoperability is achieved via industry-standard communication protocols, enabling devices to communicate fluently across diverse platforms.

Another significant characteristic of the DCP200 is its powerful data acquisition and processing capabilities. The system utilizes state-of-the-art data analytics tools to monitor real-time information, enabling better decision-making and predictive maintenance. This proactive approach helps in reducing downtime, optimizing performance, and ultimately driving operational excellence.

The DCP200 system supports a wide range of input and output options, ensuring it can interface with various sensors, actuators, and control devices. This adaptability contributes to its function as a central hub for industrial monitoring and control, enhancing data visibility and operational responsiveness.

Security is a top priority for Honeywell, and the DCP200 employs robust cybersecurity measures to protect critical infrastructure. The system includes advanced authentication protocols and data encryption techniques, safeguarding sensitive information from unauthorized access and potential cyber threats.

User experience is also a focal point of the DCP200. The platform features an intuitive graphical user interface that simplifies navigation and enhances operator engagement. Customizable dashboards provide at-a-glance insights into system performance, aiding both operators and management in identifying areas for improvement.

In conclusion, the Honeywell DCP200 is an innovative distributed control platform that marries flexibility, scalability, and security. With its comprehensive feature set and commitment to seamless integration, it stands as a vital tool for companies aiming to enhance their automation efforts and drive operational success in an increasingly complex industrial landscape.
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