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The DPC-2000 advanced control system for the Dynamitron accelerator
Radiat. Printed
Phys. Chem. Vol. in Great Britain
42, Nos
l-3,
pp. 543-546,
0146-5724/93
1993
$6.00
Pergamon
+ 0.00
Press
Ltd
THE DPC-2000 ADVANCED CONTROL SYSTEM FOR THE DYNAMITRON ACCELERATOR Bernard A. Kestler and Thomas F. Lisanti III Radiation Dynamics Inc. Edgewood, New York 11717, USA
ABSTRACT The DPC-2000 is an advanced control system utilizing the latest Its technology in computer control circuitry and components. overall design is modular and technologically advanced to keep up with customer and engineering demands. The full control system is presented as four units. They are the Local Analog and Digital I/O, Remote I/O (Input / Output), Operator Interface and the Main Computer. The central processing unit, the heart of the system, executes a high level language program that communicates to the different sub-assemblies through advanced serial and parallel communication lines. All operational parameters of the accelerator are monitored, controlled and corrected at close to 20 times per second. The operator is provided with a selection of many informative screen displays. The control program handles all graphic screen displays and the updating of these screens directly; it does not have to communicate to a display terminal. This adds to the quick response and excellent operator feedback received while operating the machine. The CPU also has the ability to store and record all process variable setpoints for each product that will be treated. This allows the operator to set up the process parameters by selecting the product identification code from a menu presented on the display screen. All process parameters are printed to report at regular intervals during a process run for later analysis and record keeping. KEYWORDS controller, Dynamitron, electron beam, e beam, control system, controls, DPC-2000, computer INTRODUCTION The DPC-2000 (DPC stands for Digital Process Controller, 2000 indicates second generation) is the control system for an electron beam accelerator called the Dynamitron, both of which are manufactured by Radiation Dynamics Inc. (RDI). The Dynamitron accelerator contains vacuum systems, high pressure gas, water cooling systems, high power electric systems from line frequency 543
544
BERNARD A.
KMTLER
and
THOMAS F. LISANTI III
to radio frequency and also includes many low voltage and current signals. For the control system these systems translate to vacuum ion gauges, vacuum gate valves, water and gas pressure and temperature sensors, three phase power control, electric power contactors, thermistors and so on. All of these systems must be controlled and monitored for proper process parameters during operation. THE DPC-2000 The DPC-2000 can be broken down into four functional sections. They are 1) Remote I/O (Input / Output), 2) Local Analog and Digital I/O, 3) Operator Interface and 4) Main Computer. All of these systems are divided into fully enclosed sub-assemblies. This gives a great deal of flexibility to the control system since sub-assemblies can be added or changed with a minimal amount of effort. The first functional section, Remote I/O, refers to the digital sense and control circuits that are terminated at some distance from the main control console. There are approximately 220 of these signals in a typical Dynamitron installation. These signals are divided among four EM1 enclosures approximately 1 m x 1 m x 0.25 m deep. Each enclosure, commonly called an 'I/O box', contains 4 tracks with 16 I/O points per track, giving a total of 64 I/O points per I/O box. Each I/O point consists of an optically isolated circuit for electrical isolation between the control system and the device. An 8 bit local embedded processor located at the end of each track continually scans each of the 16 input or output circuits they control and notes any changes. This local processor is one of the important benefits in this system because it makes the high speed communication protocol required for fast action and error avoidance simple to implement. The local processor gets commands and status requests from the main computer through a standard RS-422 communication line. This communication line attaches to each track in the system and then back to a co-processor card located within the main computer. The co-processor card contains an 80186 16 bit processor used to buffer all communication from the tracks to and from the host CPU located within the main computer. This allows the error protocol and communications demand to be off loaded to a satellite CPU for This type of off loading allows the main computer to control. dispense with the intricate high speed communication protocols and concentrate on process logic control, safety and ease of operator interface in this diverse control system. All of the dependent and embedded computer systems have power on tests that are performed to detect any obvious problems at startup, but once the system is running it depends on watchdog timers or watchdog monitors to note a problem with any particular computer. The DPC-2000 contains not only a watchdog in the main CPU, but also on the co-processor card and within each I/O track. This helps the DPC-2000 ensure that any faults during operation are dealt with immediately and properly for ultimate safety. The analog and digital I/O systems are located locally in the DPC2000 near the main computer. The analog and digital sub-systems are connected to the main computer by the use of a shielded multiconductor cable for parallel transmission of control commands and data information. The multi-conductor cable leads to simplified
8th International
Meeting
on Radiation
Processing
545
interconnects because all data flow is contained in one cable. failures means fewer from a bad or connections Fewer The parallel transmission cable allows for high misconnection. speed communication and processing of data. The information that is sent to and received from the sub-systems takes place at a rate This number simply of approximately 500,000 bytes per second. means that the computer does not waste much time in gathering or commanding information, and therefore can spend most of its valuable time dealing with the process logic, operator displays and overall command control of the Dynamitron. The fast response of the local I/O leads to more precise control of operational parameters for better machine stability and easier control for the operator by the use of graphical visual information. The DPC-2000 is capable of checking frequencies, amplitudes and digital states on many of the circuit boards located in the This allows RDI to fully test, setup and control console. calibrate all parts of the control console before they are shipped from the manufacturing plant. The software and hardware used for this QA project was generated and created in-house by RDI to maintain strict procedures and guidelines for total quality. The operator display and interface sub-systems are a very important part of the control system. The easier it is for the operator to see and comprehend all areas of the process, the more efficient the operator becomes and the less operator errors there will be. The DPC-2000 facilitates this by giving the operator all information available on the outputs and inputs to the control system in functional sections for display. These logical sections are separated into screens that are displayed on a large 20 inch diagonal monitor using a resolution of 640 by 480 pixels. This high resolution with such a large monitor allows a great deal of information to be presented to the operator. The DPC-2000 takes advantage of this data presentation ability to clearly display control status to the operator using colors and graphics for easy understanding and interpolation by the operator. There is a selection of seven screens available to the operator at the push of a button. The screens are: Main Screen, Aperture/Optics screen, Digital I/O screen, Analog screen, Safety System screen, Debug screen, and the System Fault Message screen. The Main Screen is used to assist the operator in the running of the system during a typical production run. This screen has prompt and error message areas that provide an easy and concise method of assisting the operator. The Aperture/Optics screen gives a pictorial view of the thermal electron beam locating aperture available to the Dynamitron. This informative view of where the electron beam is located after it is accelerated down the beam tube helps the technician align the beam. The Digital I/O screen provides a pictorial representation of all the remote Digital I/O used by the DPC-2000. The visual representation of the remote I/O boxes reveals at a glance the information needed by the technician that would otherwise require time consuming documentation referencing and electrical measurements. The Analog I/O screen gives the operator all the information he requires in order to ascertain operational parameters or for calibration of any analog input or output of the DPC-2000.The Safety System screen is used by the operator to note the status of any sensor within the safety system. This greatly speeds the regular inspection of the safety system sensors and makes it very easy for the operator to detect where a system violation occurred. The
546
BERNARD A. KESTLER and THOMAS F. LISANT~ III
Debug screen is, as the name implies, used only when looking for an internal error within the control system. This allows the DPC2000 to quickly provide information on whether a problem is occurring within the system or is an operator error. The Fault Message screen displays up to 15 faults that were present in the system at termination of operation to aid in the repair. The operator interface control panel is located just below the display screen, with the computer keyboard just below the panel. This layout provides an ergonomic center for the operator to adjust, start, stop and monitor all Dynamitron operations. The main computer is an IBM compatible AT system utilizing a 32 bit microprocessor and an ISA buss system. The DPC-2000 main computer contains as a minimum: - An 80386 32 bit CPU - Four megabytes of RAM memory which is used to run the control program and hold the graphic screens for fast screen switching - A Video Gate Array (VGA) card for high resolution graphics - Two RS-232 serial communication ports that are typically used to communicate to the underbeam equipment and conveyor PLCs that run product under the electron beam - One 8 bit parallel port which is attached to a printer that creates process reports listing all dynamic data and setpoints for any particular run and all error messages - A modem interface that allows immediate updates and change s to the control program during installation and setup, translating to minimal down time and no travel time for the field engineer - An I/O co-processor to handle all remote I/O communications which in turn allows more time to be spent for stable control - An 8 bit bi-directional interface card that communicates to all the local I/O such as the operator push button panel and the local analog and digital rack sub systems - One 1.4 megabyte floppy drive to load and save all data to and from the computer system including setup data and product selection parameters - One hard disk which stores the operating system, control program and all associated programs required for operation and setup of the DPC-2000 control system The DPC-2000 control system uses a sophisticated setup program in addition to the regular control program used during machine This dedicated setup program allows the field operation. technician to analyze, change and monitor important analog and needing adjustment during the setup signals and digital calibration of the control system. CONCLUSION The DPC-2000 is an advanced, state of the art control system that is flexible and easy to use. A sophisticated operator interface along with advanced high speed and precision control make the DPC2000 a paramount control system. The DPC-2000 will be a leading control system for well into the 21st century.
Phys. Chem. Vol. in Great Britain
42, Nos
l-3,
pp. 543-546,
0146-5724/93
1993
$6.00
Pergamon
+ 0.00
Press
Ltd
THE DPC-2000 ADVANCED CONTROL SYSTEM FOR THE DYNAMITRON ACCELERATOR Bernard A. Kestler and Thomas F. Lisanti III Radiation Dynamics Inc. Edgewood, New York 11717, USA
ABSTRACT The DPC-2000 is an advanced control system utilizing the latest Its technology in computer control circuitry and components. overall design is modular and technologically advanced to keep up with customer and engineering demands. The full control system is presented as four units. They are the Local Analog and Digital I/O, Remote I/O (Input / Output), Operator Interface and the Main Computer. The central processing unit, the heart of the system, executes a high level language program that communicates to the different sub-assemblies through advanced serial and parallel communication lines. All operational parameters of the accelerator are monitored, controlled and corrected at close to 20 times per second. The operator is provided with a selection of many informative screen displays. The control program handles all graphic screen displays and the updating of these screens directly; it does not have to communicate to a display terminal. This adds to the quick response and excellent operator feedback received while operating the machine. The CPU also has the ability to store and record all process variable setpoints for each product that will be treated. This allows the operator to set up the process parameters by selecting the product identification code from a menu presented on the display screen. All process parameters are printed to report at regular intervals during a process run for later analysis and record keeping. KEYWORDS controller, Dynamitron, electron beam, e beam, control system, controls, DPC-2000, computer INTRODUCTION The DPC-2000 (DPC stands for Digital Process Controller, 2000 indicates second generation) is the control system for an electron beam accelerator called the Dynamitron, both of which are manufactured by Radiation Dynamics Inc. (RDI). The Dynamitron accelerator contains vacuum systems, high pressure gas, water cooling systems, high power electric systems from line frequency 543
544
BERNARD A.
KMTLER
and
THOMAS F. LISANTI III
to radio frequency and also includes many low voltage and current signals. For the control system these systems translate to vacuum ion gauges, vacuum gate valves, water and gas pressure and temperature sensors, three phase power control, electric power contactors, thermistors and so on. All of these systems must be controlled and monitored for proper process parameters during operation. THE DPC-2000 The DPC-2000 can be broken down into four functional sections. They are 1) Remote I/O (Input / Output), 2) Local Analog and Digital I/O, 3) Operator Interface and 4) Main Computer. All of these systems are divided into fully enclosed sub-assemblies. This gives a great deal of flexibility to the control system since sub-assemblies can be added or changed with a minimal amount of effort. The first functional section, Remote I/O, refers to the digital sense and control circuits that are terminated at some distance from the main control console. There are approximately 220 of these signals in a typical Dynamitron installation. These signals are divided among four EM1 enclosures approximately 1 m x 1 m x 0.25 m deep. Each enclosure, commonly called an 'I/O box', contains 4 tracks with 16 I/O points per track, giving a total of 64 I/O points per I/O box. Each I/O point consists of an optically isolated circuit for electrical isolation between the control system and the device. An 8 bit local embedded processor located at the end of each track continually scans each of the 16 input or output circuits they control and notes any changes. This local processor is one of the important benefits in this system because it makes the high speed communication protocol required for fast action and error avoidance simple to implement. The local processor gets commands and status requests from the main computer through a standard RS-422 communication line. This communication line attaches to each track in the system and then back to a co-processor card located within the main computer. The co-processor card contains an 80186 16 bit processor used to buffer all communication from the tracks to and from the host CPU located within the main computer. This allows the error protocol and communications demand to be off loaded to a satellite CPU for This type of off loading allows the main computer to control. dispense with the intricate high speed communication protocols and concentrate on process logic control, safety and ease of operator interface in this diverse control system. All of the dependent and embedded computer systems have power on tests that are performed to detect any obvious problems at startup, but once the system is running it depends on watchdog timers or watchdog monitors to note a problem with any particular computer. The DPC-2000 contains not only a watchdog in the main CPU, but also on the co-processor card and within each I/O track. This helps the DPC-2000 ensure that any faults during operation are dealt with immediately and properly for ultimate safety. The analog and digital I/O systems are located locally in the DPC2000 near the main computer. The analog and digital sub-systems are connected to the main computer by the use of a shielded multiconductor cable for parallel transmission of control commands and data information. The multi-conductor cable leads to simplified
8th International
Meeting
on Radiation
Processing
545
interconnects because all data flow is contained in one cable. failures means fewer from a bad or connections Fewer The parallel transmission cable allows for high misconnection. speed communication and processing of data. The information that is sent to and received from the sub-systems takes place at a rate This number simply of approximately 500,000 bytes per second. means that the computer does not waste much time in gathering or commanding information, and therefore can spend most of its valuable time dealing with the process logic, operator displays and overall command control of the Dynamitron. The fast response of the local I/O leads to more precise control of operational parameters for better machine stability and easier control for the operator by the use of graphical visual information. The DPC-2000 is capable of checking frequencies, amplitudes and digital states on many of the circuit boards located in the This allows RDI to fully test, setup and control console. calibrate all parts of the control console before they are shipped from the manufacturing plant. The software and hardware used for this QA project was generated and created in-house by RDI to maintain strict procedures and guidelines for total quality. The operator display and interface sub-systems are a very important part of the control system. The easier it is for the operator to see and comprehend all areas of the process, the more efficient the operator becomes and the less operator errors there will be. The DPC-2000 facilitates this by giving the operator all information available on the outputs and inputs to the control system in functional sections for display. These logical sections are separated into screens that are displayed on a large 20 inch diagonal monitor using a resolution of 640 by 480 pixels. This high resolution with such a large monitor allows a great deal of information to be presented to the operator. The DPC-2000 takes advantage of this data presentation ability to clearly display control status to the operator using colors and graphics for easy understanding and interpolation by the operator. There is a selection of seven screens available to the operator at the push of a button. The screens are: Main Screen, Aperture/Optics screen, Digital I/O screen, Analog screen, Safety System screen, Debug screen, and the System Fault Message screen. The Main Screen is used to assist the operator in the running of the system during a typical production run. This screen has prompt and error message areas that provide an easy and concise method of assisting the operator. The Aperture/Optics screen gives a pictorial view of the thermal electron beam locating aperture available to the Dynamitron. This informative view of where the electron beam is located after it is accelerated down the beam tube helps the technician align the beam. The Digital I/O screen provides a pictorial representation of all the remote Digital I/O used by the DPC-2000. The visual representation of the remote I/O boxes reveals at a glance the information needed by the technician that would otherwise require time consuming documentation referencing and electrical measurements. The Analog I/O screen gives the operator all the information he requires in order to ascertain operational parameters or for calibration of any analog input or output of the DPC-2000.The Safety System screen is used by the operator to note the status of any sensor within the safety system. This greatly speeds the regular inspection of the safety system sensors and makes it very easy for the operator to detect where a system violation occurred. The
546
BERNARD A. KESTLER and THOMAS F. LISANT~ III
Debug screen is, as the name implies, used only when looking for an internal error within the control system. This allows the DPC2000 to quickly provide information on whether a problem is occurring within the system or is an operator error. The Fault Message screen displays up to 15 faults that were present in the system at termination of operation to aid in the repair. The operator interface control panel is located just below the display screen, with the computer keyboard just below the panel. This layout provides an ergonomic center for the operator to adjust, start, stop and monitor all Dynamitron operations. The main computer is an IBM compatible AT system utilizing a 32 bit microprocessor and an ISA buss system. The DPC-2000 main computer contains as a minimum: - An 80386 32 bit CPU - Four megabytes of RAM memory which is used to run the control program and hold the graphic screens for fast screen switching - A Video Gate Array (VGA) card for high resolution graphics - Two RS-232 serial communication ports that are typically used to communicate to the underbeam equipment and conveyor PLCs that run product under the electron beam - One 8 bit parallel port which is attached to a printer that creates process reports listing all dynamic data and setpoints for any particular run and all error messages - A modem interface that allows immediate updates and change s to the control program during installation and setup, translating to minimal down time and no travel time for the field engineer - An I/O co-processor to handle all remote I/O communications which in turn allows more time to be spent for stable control - An 8 bit bi-directional interface card that communicates to all the local I/O such as the operator push button panel and the local analog and digital rack sub systems - One 1.4 megabyte floppy drive to load and save all data to and from the computer system including setup data and product selection parameters - One hard disk which stores the operating system, control program and all associated programs required for operation and setup of the DPC-2000 control system The DPC-2000 control system uses a sophisticated setup program in addition to the regular control program used during machine This dedicated setup program allows the field operation. technician to analyze, change and monitor important analog and needing adjustment during the setup signals and digital calibration of the control system. CONCLUSION The DPC-2000 is an advanced, state of the art control system that is flexible and easy to use. A sophisticated operator interface along with advanced high speed and precision control make the DPC2000 a paramount control system. The DPC-2000 will be a leading control system for well into the 21st century.