Multidisciplinary Senior Design ConferenceKate Gleason College of Engineering

Rochester Institute of TechnologyRochester, New York 14623

Project Number: P14315

Universal Pump Data Acquisition System

Kyle Courtney Benjamin HannaIndustrial Engineering Mechanical Engineering

Matthew Joyner Steven Laplant Peter PietrantoniComputer Engineering Electrical Engineering Mechanical Engineering

Taylor Shieve Kyle TomsicElectrical Engineering Electrical Engineering

ABSTRACTA Universal Pump Data Acquisition System was designed and built for Pulsafeeder, Inc. It utilizes a

Horner APG Programmable Logic Controller to collect several operational parameters – such as pressure,flow, and critical temperatures – in a flow loop. This system integrates multiple sensors including flowmeters,pressure transducers, thermocouples, and a VFD which communicates motor characteristics. The system iscompatible with industry standards, accepting standard inputs such as 4-20 mA analog inputs and T-typethermocouples, so that sensors may be chosen based on what is applicable to a given system. The data iscollected and stored by the PLC and then offloaded onto a computer via an SD card. The computer thenanalyzes the data to show trends using a Microsoft Excel macro. The system may collect data for varyingamounts of time, depending on the user’s input of sample rate. To demonstrate the system’s capabilities, atest station was built to collect data from an Eclipse E05 Pump. It includes a flow loop constructed with 1/2inch Schedule 80 PVC piping, two Yokogawa Flow Meters, two Omega Pressure Transducers, and six T-typethermocouples.

Nomenclature

Abbreviation TermCSV Comma-Separated Values (a common data format)

E-Stop Emergency StopNEMA National Electric Manufacturers Association

PLC Programmable Logic ControllerSBC Single Board ComputerSD Secure Digital (a flash memory card format)

SMS Short Message Service (text message)TCP Transmission Control Protocol

UPDAS Universal Pump Data Acquisition SystemVFD Variable Frequency Drive

Copyright © 2014 Rochester Institute of Technology

Proceedings of the Multi-Disciplinary Senior Design Conference Page 2

1 BackgroundPulsafeeder Engineered Products is a Rochester-based manufacturer of pumps that was in need of a pump mon-

itoring system. In the pump design process, it is necessary to track pressures, flow rates, temperatures, and otherquantities of interest to ensure safe and proper pump operation. Originally, Pulsafeeder performed these measure-ments manually, recording three data samples every hour for each quantity of interest. This measurement system isboth time- and cost-inefficient and provides a perfect opportunity for automation.

Similar pump data acquisition systems are already available in the market – such as a data acquisition systemby RR Pump Inc. The team considered these and similar data acquistion tools such as the data loggers designedby CAS Data Loggers and Labview – a tightly-integrated measurement and analysis ecosystem offered by NationalInstruments. The team used these other products for benchmarking purposes. The systems by RR Pump Inc. provideall of the necessary data, but are integrated into the pump head, which would require modification of Pulsafeeder’sexisting pumps. CAS Data Loggers’s offerings are sampled at 25 Hz, which is too low of a frequency for this project.Further, they offer more features than needed for this project and have stricter requirements (such as the need forAdobe Flash Player 10) than would be acceptable for this project. While Labview provides a rich and well-integratedsuite of tools for gathering and analyzing data, the licensing costs may be prohibitive for our customer, and Labview’sproprietary nature may prevent the project from being productized in the future.

2 Design ProcessThe pump monitor system is required to monitor the following quantities:

• Volumetric Flow rate

• Gage and Vacuum Pressure

• Motor current (in all three phases)

• Motor voltage (in all three phases)

• Critical temperatures

• Efficiency

• Power

• Torque

• RPMFurther, the system needs to be safe and protect both the user and the motor through shutdowns when unsafe

conditions are observed; this is achieved by the inclusion of a visual indicator of pump status, and by providing asoft start to extend motor life. The system needs to be capable of collecting and analyzing data. The system alsoneeds to be portable to facilitate data gathering at different stations. The customer expressed great interest that thesystem use primarily off-the-shelf components to facilitate the construction of additional units and to simplify thereplacement of parts should the need arise. Finally, the customer expected an expandable, portable, and compact unitcapable of integrating with existing pump systems of all sizes and environments. The project budget was $15,000;some materials, such as the laptop, pump, and motor, were provided by the customer.

There were two major design concepts: one centered around the use of a PLC and the other around an SBC ormicrocontroller. While both approaches had strengths and weaknesses, the team decided to pursue the PLC conceptbecause it is an industry standard and is likely more durable than the microcontroller/SBC approach would be. Thecustomer also expressed more interest in the PLC route, as ladder logic (the primary language used for PLC program-ming) is an industry standard. Consequently, the PLC would be easier for the customer to maintain. Consequently, theteam decided on the block diagram in Figure 1.

A test station for the use of demonstrating at the Imagine RIT Innovation Festival was constructed in parallelwith the UPDAS. The test station includes a mobile metal cart, 1/2-inch Schedule 80 PVC piping, two flow meters,two pressure transducers, six thermocouples, and an E-stop safety feature. It utilizes a Pulsafeeder Eclipse E05 Pumpdriven by a Baldor Dirty Duty Motor. The test station will be delivered to the customer. It should be noted that the teststation is an independent deliverable and is not a part of the UPDAS. The design of the station demonstrates how theUPDAS works and is consistent with existing flow loop systems located at Pulsafeeder.

Project P14315

Proceedings of the Multi-Disciplinary Senior Design Conference Page 3

Figure 1. Block diagram for the final UPDAS design

3 Results and Discussion3.1 The Main Enclosure

The main enclosure houses the PLC, provides safety for personnel, and allows for sensors and communications tobe interfaced with the PLC. The enclosure is an off-the-shelf NEMA 12 enclosure which will provide protection to theinternal parts from any possible splash damage. To ensure system expandability, the system includes three thermocou-ple SmartRail modules (allowing a total of up to twelve thermocouple inputs) and one analog input SmartRail module(enabling an additional four analog inputs). These modules are mounted to a SmartRail Ethernet Base interfaced withthe PLC via networking cables terminated with RJ45 connectors. The PLC and all other electrical equipment withinthe main enclosure requires 24 volts. The power analysis used to determine the necessary power supply for the systemcan be viewed in the table below.

Table 1: Power analysis assuming 24V DC supplyItem Quantity Current (A/unit) Total Current (A) Power (W/unit) Total Power (W)PLC 1 0.17 0.17 4.08 4.08

Smart Rail 4 0.1 0.4 2.4 9.6Ethernet Base 1 0.55 0.55 13.2 13.2

Total 1.12 26.88

3.2 SensorsIn order to maintain the pump’s universality, standard 4-20 mA inputs are used for pressure transducers and flow

meters. This allows the sensors to be replaced for different systems with the addition of a simple calibration step.Further, any sensor that uses the industry standard of 4-20 mA may be used with our system. For simplicity, wechose Omega Pressure Transducers and Yokogawa Flow Meters which form a ”family” of sensors covering most ofPulsafeeder’s applications.

Project P14315

Proceedings of the Multi-Disciplinary Senior Design Conference Page 4

Similar to the 4-20mA flow and pressure sensors, the temperature sensors are a standard T-type thermocouples.This means additional or replacement thermocouples may be used as long as they maintain this standard.

3.3 Emergency Stop SubsystemTwo of the customer’s highest priority needs concerned operator and system safety, the emergency stop function-

ality was designed as a separate subsystem. The emergency stop is triggered via a stop button, which immediately cutsthe power to the VFD (and consequently to the motor) via a relay. The emergency stop system is enclosed in a NEMA4 rated enclosure to prevent water from damaging the internal components. This case also allows the emergency stopbutton to be moved to where ever is most convenient for the operator.

This system was also designed with extendability in mind: the only limiting factors to the emergency stop systemare the circuit breaker and relay current capabilities. If the customer would like to continue to use the emergency stopfunctionality on a system with a current draw larger than 10A, these parts may easily be swapped for ones with greatercapabilities.

This subsystem was also integrated into the PLC programming. When connected and in the unpressed state, thebutton sends a logical high signal to the PLC indicating that power to the VFD is live. When the button is pressed, thissignal is brought to a logical low. This signal allows the PLC to log the appropriate fault code and also suggests thatdata collection should end. Since the signal is active low, however, it will also be triggered if the connection betweenthe PLC and the button becomes severed. Consequently, the PLC is programmed to send a “stop” signal to the VFD,in case the system is still running.

3.4 Test StationThe team designed the test station in Figure 2 to demonstrate the capabilities of UPDAS. This test station consists

of a flow loop on a cart, with an integrated Eclipse E05 pump and 0.5 HP Baldor motor. The station also includessix thermocouples, two pressure transducers (for suction and discharge pressure measurements), and two flowmeters(for suction and discharge flow rates). While not a part of UPDAS per se, the test station was invaluable for validatingUPDAS and may be used by Pulsafeeder in the future for testing Eclipse Series pumps with relatively low output.

Figure 2. The completed test station

Project P14315

Proceedings of the Multi-Disciplinary Senior Design Conference Page 5

Figure 3. Flowchart describing PLC program design

3.5 PLCAfter deciding to use a PLC for processing the sensor inputs, the team proceeded with the design of the program

that would run on the PLC. This program was outlined using the flowchart in Figure 3. Additional supporting materialswere also drafted: a register map, containing a listing of every register used in the program with its address offset, asymbolic name, description, and initialized value; a listing of fault codes to report, to maintain consistency with theanalysis program; and a template for the CSV format, to enable the analysis program to decode the data provided bythe PLC.

Following the completion of the design phase – and after receiving approval to move on to construction – theteam collected resources for learning ladder logic, the industry-standard programming language used for program-ming PLCs. The team then began to translate the flowchart into ladder logic code and to configure the PLC to processthe appropriate networking protocols. The PLC receives data from the SmartRails using a Modbus over TCP connec-tion; the SmartRails were assigned static IP addresses and the PLC was configured to place the received data in theappropriate registers.

VFD communication was established over an RS485 cable using the serial Modbus protocol. Unlike the Smar-tRail connections, connection with the VFD was slightly more involved, since the VFD is used for control and datagathering purposes. The data gathering configuration was simple, and only required the necessary VFD and PLCregister addresses. For control, however, the team had to design the packets that are sent to the VFD for starting

Project P14315

Proceedings of the Multi-Disciplinary Senior Design Conference Page 6

and stopping motor operation. After reviewing the VFD documentation, these were properly formatted to send theappropriate signals to the VFD.

One concern that was presented was that the system may start in a fault condition. While this is indeed possible, itwill begin issuing a “stop” command to the VFD as soon as the fault condition is detected. The current architecture wasnecessary because some measurements (e.g. flowrate) might be considered out of bounds before the system starts, butare considered reasonable during startup and normal operation. If the risk of starting in a faulty condition is deemedtoo high, the software may be restructured to include a check before starting the motor.

3.6 Data Analysis SoftwareDue to the low-level nature of ladder logic and the PLC’s relatively limited resources (compared to a standard

desktop PC), the analysis of the gathered data is offloaded to a PC running Microsoft Excel. The team has designedan Excel macro that will import and plot the data from PLC. While the primary storage medium for the PLC data isan SD card, the macro was written to accept files from any user-determined location, so that locally-saved or networkaccessible storage are viable options as well.

This macro must also stitch together the data across all of the collected CSV files. Due to row limits imposed byExcel, the PLC is programmed to create a new CSV file every time it has recorded approximately one million datapoints (Excel is limited to 220 or 1,048,576 lines in a spreadsheet, and some additional lines are reserved for headerinformation). While the resulting data sets may not be concatenated vertically, they may be concatenated horizontally,which is exactly how the macro circumvents Excel’s row limitation.

To improve usability, the Excel macro was also fitted with a graphical user interface. This enables the userto import the desired CSVs, stitch them together, and generate plots between any three measured quantities (oneindependent and up to two dependent variables) by pressing buttons, rather than navigating through the Excel menusto find the appropriate macro calls.

4 ConclusionsOverall, P14315 was a successful project. The customer is satisfied with the resulting product, and UPDAS

achieves its intended purpose: the acquisition of pump data through an interface that does not rely on a specific modelof pump.

Despite the team’s success, some changes would be made if the design process were redone. For example, the PLCprogramming would likely have been done using structured text rather than ladder logic. In ladder logic, programs aredesigned visually using schematic-like drawings consisting of power rails, contacts, relays, and function blocks. Whilethis environment may be familiar to electrical engineers in the manufacturing industry, it presented a learning curveto the team, some of whom lack any experience with relays and contacts. Structured text is an alternative industry-standard PLC programming language. It is text-based, however, which would allow the team to draw on their previousprogramming experience, since most traditional programming languages – such as C, C++, or Java – are text-based.

Ultimately, however, there are still possibilities for future work. In its current state, UPDAS is limited in its controlcapabilities. The system could be extended to control the accelerations experienced by the motor during startup, or tovary the motor speed over time.

The team has exposed a LAN port to the PLC to enable communication with the PLC over ethernet, but thesecapabilities are not currently configured. Enabling these features opens a wealth of possibilities: remote access ofdata, remote control of the motor and pump (assuming the aforementioned VFD control interface is implemented),and even automated alerts (via email or SMS) when the pump exceeds user-imposed limits.

5 References[1] McCabe, R., 1984, Metering Pump Handbook, 2nd ed., Prentice Hall, New York, NY, Chap. 6.[2] Pritchard, Phillip J., 2011, Fox and McDonald’s Introduction to Fluid Mechanics, 8th ed., John Wiley & Sons, Inc.,

Project P14315

Proceedings of the Multi-Disciplinary Senior Design Conference Page 7

Hoboken, NJ.

AcknowledgementsThe team would like to thank the following individuals and organizations for their assistance with this project.

Without their contributions, this project would not have been successful:

• Leo Farnand, the team’s faculty guide, who provided support and guidance throughout the design process;• John Condame, the team’s primary customer liaison, who, in addition to fulfilling the role of customer, was able

to assist the team with design and implementation insights;• Pulsafeeder Engineered Products, the project’s sponsor, who provided the resources for this project to be designed

and constructed;• and the faculty and staff of the Rochester Institute of Technology, who provided the team with the knowledge,

experience, resources, and support necessary to design and implement this system.

Project P14315