PLC based process control engineering guide

... Operation and control In many processes, a physical variable such as temperature, pressure or voltage has to take up a specified value, and maintain it as accurately as possible A simple example is a ... numerical values, and uses them to calculate the manipulating variable This has certain advantages compared with analog processing: - increased accuracy of control, depending o...

Ngày tải lên: 13/12/2013, 00:14

... PLC COMMUNICATIONS IN A PROCESS CONTROL SYSTEM by GR MacKenzie, AEG Communication has become a major part of any process control automation system Today PLC communication is as much for data acquisition ... 56 interfaces A ninth user is an additional lines and 16 interfaces This is clearly very expensive in hardware and installation 1 (a) Point-to-point topology 1(...

Ngày tải lên: 25/12/2013, 08:50

... phase modulation: a) a phase shift of 180( in the carrier occurs each time a binary zero is transmitted No phase change takes place for a binary b) phase shift keying (PSK) in which a zero and ... variations and combinations of these techniques which result in more than one bit per baud Baseband and broadband The principle characteristics of base-band and broadband systems are...

Ngày tải lên: 25/01/2014, 05:20

... variables 1. 9 Main areas of control engineering Today, control engineering has applications in almost every area of technology In Chapter 1. 1 we have already seen that these different applications ... already discussed in Chapter 1. 3, “Operation and control , a parameter can be kept constant by suitable operation An example could be to maintain a constant furnace temper...

Ngày tải lên: 07/08/2014, 15:20

... Temperature small electrically-heated oven large electrically-heated furnace large gas-fired reheating furnace autoclave high-pressure autoclave injection molding machine extruder packaging machine ... a change in manipulating variable is only reproduced in the process variable after the dead time has elapsed If the change in manipulating variable was too large, there is a time interval b...

Ngày tải lên: 07/08/2014, 15:20

... controllers takes up a value such that the resulting manipulating variable is just sufficient to maintain the process variable at a constant value A P controller always has a permanent control deviation ... detail under 3. 2.2 3. 2.2 Permanent deviation and working point A P controller only produces a manipulating variable when there is a control deviation, as we already k...

Ngày tải lên: 07/08/2014, 15:20

... quality (see Fig 46 ) Linear control area (linear optimum): [A] min = A1 - A2 + A3 Magnitude control area (magnitude optimum): [A] min = | A1 | + | A2 | + | A3 | + Squared control area (squared ... disturbance is taken as 10% of yH In addition to the overshoot amplitude and the stabilization time, for mathematical analysis, the area of the control error is also used as a...

Ngày tải lên: 07/08/2014, 15:20

... A modulating controller does not receive an actuator retransmission signal and must always assume a linear actuator action If the actuator has a non-linearity, or play is present in the actuator ... PD/PID Table 8: Control configurations of a quasi-continuous controller, and actual control actions Example: A quasi-continuous controller configured as a proportional controller a...

Ngày tải lên: 07/08/2014, 15:20

... available to measure disturbances and maintain them constant An example of this is the temperature control of a gas-fired annealing furnace Here, the main disturbance, gas pressure, can be maintained ... transfer from automatic to manual mode, where the manipulating variable remains at its current value, and can then be changed manually In case of a broken probe, caused, for example,...

Ngày tải lên: 07/08/2014, 15:20

... deaths TABLE Characteristics of cases and two control groups: Population- based case -control study of smoking on risk of cancer deaths among Chinese men 1989–1991 Characteristic Cases No of subjects ... sex-matched living spouse control design as an alternative control selection for a nationwide population- based case -control study is valid and feasib...

Ngày tải lên: 26/10/2012, 09:48

... Industry Standards D-1 D-1 D-2 Identify-Based Networking Systems Configuration Guide Version 1.0 December 2005 vii Contents Identify-Based Networking Systems Configuration Guide viii Version 1.0 December ... company (0403R) Identify-Based Networking Systems Configuration Guide © 2005 Cisco Systems, Inc All rights reserved C O N T E N T S CHAPTER Introduction to...

Ngày tải lên: 22/10/2013, 16:15

... between Grid Control and Application Server Control Oracle TIGHT / Oracle Enterprise Manager 10g Grid Control Implementation Guide / Michael New / 149275-5 26   Oracle Enterprise Manager 10g Grid Control ... Chapter 3, we’ll install Grid Control and get this thing on the road Chapter Grid Control Preinstallation 29 30   Oracle Enterprise Manag...

Ngày tải lên: 06/11/2013, 10:15

... 10gR2 10.2.0.1 OEM 10g Grid Control Release (10.1) EM 10gR1 10.1.0.6 OEM 10g Grid Control Release (10.1) EM 10gR1 10.1.0.5 OEM 10g Grid Control Release (10.1) EM 10gR1 10.1.0.4 OEM 10g Grid Control ... OEM 10g Grid Control Release (10.2.0.4.0) EM 10gR4 10.2.0.4 OEM 10g Grid Control Release (10.2.0.3.0) EM 10gR3 10.2.0.3 OEM 10g Grid Control Release (1...

Ngày tải lên: 06/11/2013, 10:15