Tag Archive: communications

Dec
09

Using Wireless Measurements In Control Applications

Using Wireless Measurements in Control

Wireless transmitters may be preferred in applications where new measurements are required since the cost may be lower than that associated with installing wired transmitters. However, there is a significant differences in the frequency and manner in which a new measurement value is updated by a wired transmitter vs. a wireless transmitter. Such differences must …

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Nov
26

Addressing Control Applications Using WirelessHART Devices

Addressing Control Applicatons Using WirelessHART Devices

I traveled to Germany earlier this year for a meeting with Namur to present Emerson’s approach for addressing control applications using WirelessHART devices. WirelessHART transmitters have been installation by many plants in Europe. The reliability of these devices has been well established and many of these plants are now interested in using WirelessHART transmitters in …

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Apr
23

Control Using Wireless Devices – Conclusions

Field experience using WirelessHART in control applications may be summarized in the following manner: WirelessHART measurements may be used in closed loop control applications.  Window communications mode minimizes power consumption PIDPlus is a standard feature of DeltaV and works with standard WirelessHART devices.  Standard DeltaV Tools support Simulation and Tuning. The performance of PIDPlus in …

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Apr
16

Control Using Wireless Devices – Field Results Part 2

Table 2 Field Evaluation of Wireless Control at UT

The Separations Research Program was established at the J.J. Pickle Research Campus in 1984. This cooperative industry/university program performs fundamental research of interest to chemical, biotechnological, petroleum refining, gas processing, pharmaceutical, and food companies. CO2 removal from stack gas is a focus project for which WirelessHART transmitters were installed for pressure and steam flow control …

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Apr
09

Control Using Wireless Devices – Field Results Part 1

Bioreactor pH Control Using PIDPlus and WirelessHART Transmitter

Broadley James manufactures bioreactors and control systems (based on DeltaV) that are used in the life science industry. To explore the use of WirelessHART transmitters in bioreactor control, a portable Hyclone 100 liter disposable bioreactor was instrument with a Rosemount WirelessHART gateway and transmitters for measurement and control of pH and temperature. A WirelessHART transmitter …

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Apr
02

Control Using Wireless Devices – Control Performance Part 2

Response  During Disturbance Recovery

The reliability of WirelessHART device communication has been well established. Even so, in the event of loss communication, the expected control behavior is of interest. The simulation environment was used to compare the behavior of the PIDPlus for loss of communications to a PID with a wired transmitter where the measurement value is frozen for …

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Mar
26

Control Using Wireless Devices – Control Performance Part 1

Table 1 Control Performance Wired vs. Wireless

When the PIDPlus is used with a wireless transmitter in a control application the performance will be comparable to that achieved using a wired transmitter with a wired transmitter. To demonstrate this, the module shown below was created in DeltaV that allows the control using PIDPlus using s wireless communication to be compared to the …

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Mar
19

Control Using Wireless Devices – The Solution Part 2

Derivative Calculation in PIDPlus

In Solution Part 1 we examined that can be made in the PID reset to accommodate slow and/or non-periodic measurement update. To further enhance the response for continuous changes in setpoint the implementation of the PIDPlus may be modified as shown below. This PIDPlus implementation is standard in DeltaV v12 and allows the reset calculation …

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Mar
12

Control Using Wireless Devices – The Solution Part 1

PIPlus Reset Filter Calculation

As mentioned my previous block, the communication capability of WirelessHART devices and a modification in the way the PID enable control using wireless devices. The standard communication techniques that are supported by a WirelessHART device are defined in HART 7 specification that has been adopted as an international standard, IEC 62591Ed. 1.0. The device may …

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Dec
13

Tutorial Series – Foundation Fieldbus

As noted in a previous post, when work on Foundation Fieldbus specification was completed in 1994, there were very few fieldbus products on the market and even fewer control systems that supported these devices. The Fieldbus Foundation function block team discussed the need to communicate the advantages of fieldbus to inform the industry of this …

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