- Email: [email protected]
The new Fermilab main ring control system
Nuclear Instruments and Methods in Physics Research A293 (1990) 267-270 North-Holland
THE NEW FE
LA
IN
267
NG CONTROL SYSTEM
K. SEIKO, L. ANDERSON, R. DUCAR, A. FRANCK, J. GOMILAR, B. HENDRICKS and J. SMEDINGHOFF Fermi National Accelerator Laboratory *, PO Box 506, Batavia, IL 60510, USA
The Fermilab Main Ring control system has been operational for over sixteen years. Aging and obsolescence of the equipment make maintenance difficult. Since the advent of the Tevatron, considerable upgrades have been made to the controls of all the Fermilab accelerators except the Main Ring. Modernization of the equipment and standardization of the hardware and software have thus become inevitable . The Tevatron CAMAC serial system has been chosen as a basic foundation in order to make the Main Ring control system compatible with the rest of the aaxlerato. complex. New hardware pieces including intelligent CAMAC modules have been designed to satisfy unique requirements. Fiber-optic cable and repeaters have been installed in order to accommodate new channel requirements on a saturated communication system .
1. Inhuducdon The first-generation Fermilab Main Ring control system was installed in the early 1970s. The equipment has aged, and obsolescence of some of the parts has made maintenance work difficult. Since the advent of the Tevatron, considerable upgrades have been made to the controls of all the accelerators except the Main Ring (although some improvements have been made to the Main Ring by adding necessary modules in Tevatron crates). Modernization of the equipment and standardization of the hardware and software have thus become essential. The CAMAC serial system, which had been used for the Tevatron, has been chosen as a basic foundation in order to make the Main Ring control system compatible with the rest of the accelerator complex. This work was begun in early 1988 . Copies of soine CAMAC modules which had been developed for the Tevatron have been constructed ; also new types of modules and a new interface chassis have been developed and constructed . An eight-channel transient recorder (CAMAC 193) has been developed to record and analyze voltage-toground signals on the main busses when a ramp trip w 111 occurs. A description oI the 193 173 inoutuc iss giveia âi. section 2.1 . A quad waveform generator (CA MAC 453) has been developed to control twelve dipole-correction element power supplies per building . The module is flexible, capable of generating waveforms for series of cycles with different energy levels and of updating waveforms at a rate of 720 Hz . A description of the 453 * Operated by Universities Research Association Inc., under contract with the US Department of Energy .
module is given in section 2.3. Other newly developed hardware pieces are the vacuum-readback interface (CAMAC 145) and status-control interface (SCI), whose descriptions are given in sections 2.2 and 2.4, respectively. Brief descriptions of other support systems (fiber-optic link, Main Ring power-supply link and Main Ring abort system) are given in sections 3.1-3 .3 . The Main Ring control system, including the frontend computer and the fiber-optic link, is shown in fig. 1.
2. New developments Z.1 The eight-channel transient recorder (CAMAC 193) The Main Ring has four magnet busses ("bend lower", "bend upper", "quad focus" and "quad defocus"). Each has a number of magnets and a number of power supplies connected in series . Voltages measured on these busses with reference to ground are monitored so that they can be properly operated and maintained. The CAMAC 193 module monitors the magnet bus voltages in three different modes ("single-channel read", "snapshot" and "transient record"). In the single-channel read mode, the host co puict can Head 6hc tnmd= stamp and the ADC data on a specified channel at its 9cistiHe. In the snapshot mode, the host specifies an arm event and a delay value. e 193 module collects data for all eight channels after the specified delay from the arm event. All the 193 modules that are distributed around the ring collect data for eight channels at the specified time. The operator can then read and plot the data on a graphic display. Such a plot enables him to
0168-9002/90/35,033 -5 0- (0 1990 - Elsevier Science Publishers B.V . (North-Holland)
VII. HARDWARE
K Seino et al. / The new Fermilab Main Ring control system
268
examine voltage distributions on the magnet busses, which allows him to locate faulty power supplies or bus ground faults. In the transient record mode, the host specifies an arm event and a number of sample triggers. The 193 module continuously collects and stores data in a circular memory buffer (2 kbytes per channel) for eight channels, and it stops the data collection at the specified number of sample triggers after the arm event. The operator can later read and plot the data from all the 193 modules around the ring. By plotting these data for different times before and after the arm event, he can tell what has happened to the magnet bus voltages as functions of time. The 193 module is double-width ; one board is a computer/ CAMAC interface which contains a Z8002 CPU, RAM, PROM, clock-event sources, interrupt controllers, a multichannel timer and a CAMAC interface . The second is a peripheral board which consists of a 10 Its 12-bit ADC subsystem and a time-stamp counter. K. Seino designed the hardware and J. Smedinghoff wrote the firmware for the 193 module [1] .
The CAMAC 145 module was designed with the Motorola MC68000 microprocessor and the MC68881 floating-point coprocessor . The serial vacuum data which come from a vacuum scanner unit are first converted to parallel, whose special BCD format is then converted to IEEE standard floating-point by the coprocessor . The module calculates an average reading from up to 63 channels off vacuum data approximately once a minute, excluding bad readings. It also generates alarms when the average vacuum value is out of limits or when 15 or more pumps are returning bad readings. Distributed intelligence to do floating-point conversion, averaging and alarm scanning was not available on the old Main Ring control system. Its addition will reduce the computational burden on the front-end computer, and the standard data format wiïl allow Main Ring vacuum devices to be placed on Eermilab's parameter pages and datalogger lists. K. Seino designed the hardware and B. Hendricks .-s?-,,e for the 145 module [2]. wrote the firm,
2.2. The vacuum-readback interface (CAMAC 145)
2.3. The quad waveform generator/ power-supply controller (CA MAC 453)
It was decided not to make extensive modifications to the entire Main Ring vacuum-control subsystem, but only to make some improvements on its readback. In this subsystem, control operations are performed via separate hardware pieces, which consist of digital input and output modules, and an SCI unit.
Main Ring operation has gradually become more complicated with the advent of the Tevatron . The accelerator is presently operated with a number of cycles, each of which may deal with a different energy level and serve a different purpose (e.g., proton acceleration, antiproton acceleration, bunch coalescing, studies, etc .).
SST SERVICE BUILDING
ACNE i
2NO SERVICE BUILDING
REPEATER REPEATER
FIBER OPTIC
LINK
FIBER WTIC LINK
REPEATER
TO 3AD BUILDING
CAMAC CRATE MR FRONT
2 B
HÎ84
T S C C
6I3I3r3
CAMAC CRATE
ACNET
VACUUM
MUX'0
SCANNER
AOC
V
PUMP
Fig. 1 . The new Fe
SIGN"
MR PS VOLT MCNIT
VULTAGE TO GFKXM SI
STATUS CONTROL INTERFACE
' . DITS
ûTATLG
DITS
MRPS
INPUT
CONTROLLER
PANEL 717
M§
"ir4 S
E8AIPA
PING
SUPPLIES
i WAa
DEMMŒ
'lab Main Ring control system including the front-end computer and the fiber-optic link .
K Seino et al. / The new Fermilab Main Ring control system
269
Fib 1. The CPU board of the CAMAC 453 quad waveforni generator module .
In order to satisfy continually changing requirements, a series of CAMAC waveform generators has been developed, starting from simple modules (160, 165 and 265), through a moderately complicated one (365), to a complicated and flexible one (453). One board of the double-width 453 module is a computer/CAMAC interface which contains an Intel 80960 microprocessor, MK PROK a TCLK (Tevatron clock) decoder, an MDAT (a link distributing accelerator parameters in real time) interface, a CAMAC interface and digital input/output circuits. The second is a peripheral board which consists of a four-channel DAC and additional digital input/output circuits . The 453 module is capable of generating four semiindependent analogue outputs at a rate of 720 Hz and of performing digital controls for up to four dipolecorrection-element power supplies. The characteristics of the anaallogue outputs. are desenibed bellow. (1) Output wavefor?ns : output = A * ml * f(t) + st * m2 * + sf3 * m3 * h(M2),
where sil, sf2 and sß are constant scale factors having a range of -128.0 to + 127 .9, ml, m.2 and m3 are raw MTEAT readings divided by 256, f(t) is an inte,7-polaied function of time and g(MI) and h(M?) are interpolated functions of the MDAT parameters .
(2) Tables : each term in the output functions has eight possible tables with up to 32 entries each. Table selection is affected by an interrupt. Sixteen interrupt the levels are available, each being awnted by "OR" of up to eight TCLK events. Upon assertion of an interrupt, the module starts using three user-specified taW; (one for each term in the output function) for each of the four output waveforms. The CPU board is densely populated, as shown in 2. In order to accommodate many functional blocks (some of them of high speed) in a limited space, the board was designed with the latest components available. Some of these are : an Intel 80960KA CPU, Fujitsu 81C78A RAMs, Cypress CY7C251 PROW Alters Eh 5032s and EPM5128s. A. Franck and J. Gomilar designed the hardware and B. Hendricks wrote the firmware for the 453 module t 3lj. 2.4. Statvs-c.° ontrol interface - the SC! unir In order to control and monitor the Main Ring magnet busses and power supplies and other support systems (vacuum, cooling and safety), a large number of digital input and output bits must be read and set . To meet this requirement, L. Anderson designed the SCI chassis, which is interfaced to the CAMAC system VIL MMWAM
270
K Seino et al. / The new Fermilab Main Ring control system
via CAMAC 186 and 284 modules. The 186 provides up to 256 bits of digital input with an external multiplexing chassis . A multiplexer card residing in the SCI decodes four address lines which originate at the 186 module, to select one of sixteen digital input channels . The 186 also provides twelve pulsed control bits, which are distributed to external devices via the SCI . The 284 module provides sixteen additional control bits which are fed to a relay box, again via the SCI . Relay contacts are used to turn on/off pumps and valves for the vacuum and water-cooling systems. The SCI consists of a 7 in x 19 in Euro-crate, Euro type-3U plug-in cards and a plug-in power-supply module. It also has a local channel select/monitor facility for digital inputs.
The active signal of the abort loop is a 5 MHz square wave, originated by the 201 module and transmitted around the ring via the fiber repeater/link system. The presence of an active signal on the abort loop, as received back by the adjacent 200 module, is interpreted as "beam permit" . The cessation of this signal, as detected there, is interpreted as "abort" . When this condition occurs, a CAMAC 279 Beam Sync clock interface/ timer module generates a trigger to abort the Main Ring beam. The CAMAC 200 modules are located in each of the 30 service buildings around the ring. They receive the upstream status of the link and provide local permits to allow the 5 MHz signal to pass downstream. CAMAC modules 200, 201 and 279 were designed by R. Ducar for Tevatron applications 16,71 .
3. Other support systems
4. Current status
3.1. Fiber-optic link
A five-month shutdown started at the end of June 1989 and the conversion of the controls has been proceeding since that time. Removal of old equipment and cables was done first; equipment-rack and cable tray installations followed . Now, at the end of October, 1989, major cables have been pulled, and a majority of hardware pieces have been installed . Most software has been completed, and testing of different subsystems is beginning . By the early part of January 1990, the entire accelerator, including the Main Ring, is expected to be operational and accelerating beam again.
Because of ever increasing demands for communication media, all 19 originally installed cables in the Main Ring/ Tevatron area are utilized. To overcome the resulting shortage and to meet requirements for future expansion, an optic trunk cable containing 24 fibers has been installed. Optic repeaters have been designed, built and installed for use with these fibers for the Main Ring CAMAC serial system, the Main Ring power-supply link and the Main Ring abort system. R. Ducar designed the fiber-optic repeaters, and the fiber-optic link was installed under his supervision . 3.2. Main Ring power-supply control system (or link)
Acknowledgements
The Main Ring power-supply system consists of a number of supplies, which energize three separate magnet busses ("bend", "quad focussing" and quad defocussing"). The power supplies are located in 15 of 24 service buildings distributed around the ring. During typical operation, the current ramps from 100 to 1700 A with a cycle time of 10 s. The control system for the Main Ring power supplies consists of two DEC PDP 11,'55 minicomputers, a link transmitter, and link receiver modules (CAMAC 269"l" The transmitter ifaû deûiped vy D . Mahler ; It 1s capable of generating 10 Mbit/s data frames and sending ramp data to all the power supplies at 720 Hz. The 269 module, designed by R. Ducar, receives ramp data : nd transmits them to the power supplies 14,51.
We wish to express our appreciation to our manager, P. Lucas, for his guidance and support . We also wish to thank R. Crouch, T. Gierhart, R. Hagler, T. Hendricks, D. Jarvis, R. Klecka and R. Koldenhoven for their hard work in constructing and installing the hardware pieces .
3.3. Main Ring abort loop The Main Ring abort loop consists of a source module (CAMAC 201), a repeater/link system and abort-concentrator modules (CAMAC 200).
References [1] K. Seino and J. Smedinghoff, Fermilab Controls Hardware Release no. 69.1 (i989) . [21 K. Seino and B. Hendricks, Fermilab Controls Hardware Release no. 70.1 (1989) . [3] A. Franck, J. Gomilar and B. Hendricks, Fermilab internal memo (1989). [4] R. Ducar and R. Mahler, Fermilab Controls Hardware Release no. 65.0 (1989). [5] R. Ducar, Fermilab Controls Hardware Release no. 66.0 (1989). rcl " rte_ ._. __ r____ ". L " N Y\. LJi1CQl, I'elllulab inter nal !91G!ήo [7]
(1982).
R. Ducar, Fermilab Controls Hardware Release no. 43.0 (1985) .
THE NEW FE
LA
IN
267
NG CONTROL SYSTEM
K. SEIKO, L. ANDERSON, R. DUCAR, A. FRANCK, J. GOMILAR, B. HENDRICKS and J. SMEDINGHOFF Fermi National Accelerator Laboratory *, PO Box 506, Batavia, IL 60510, USA
The Fermilab Main Ring control system has been operational for over sixteen years. Aging and obsolescence of the equipment make maintenance difficult. Since the advent of the Tevatron, considerable upgrades have been made to the controls of all the Fermilab accelerators except the Main Ring. Modernization of the equipment and standardization of the hardware and software have thus become inevitable . The Tevatron CAMAC serial system has been chosen as a basic foundation in order to make the Main Ring control system compatible with the rest of the aaxlerato. complex. New hardware pieces including intelligent CAMAC modules have been designed to satisfy unique requirements. Fiber-optic cable and repeaters have been installed in order to accommodate new channel requirements on a saturated communication system .
1. Inhuducdon The first-generation Fermilab Main Ring control system was installed in the early 1970s. The equipment has aged, and obsolescence of some of the parts has made maintenance work difficult. Since the advent of the Tevatron, considerable upgrades have been made to the controls of all the accelerators except the Main Ring (although some improvements have been made to the Main Ring by adding necessary modules in Tevatron crates). Modernization of the equipment and standardization of the hardware and software have thus become essential. The CAMAC serial system, which had been used for the Tevatron, has been chosen as a basic foundation in order to make the Main Ring control system compatible with the rest of the accelerator complex. This work was begun in early 1988 . Copies of soine CAMAC modules which had been developed for the Tevatron have been constructed ; also new types of modules and a new interface chassis have been developed and constructed . An eight-channel transient recorder (CAMAC 193) has been developed to record and analyze voltage-toground signals on the main busses when a ramp trip w 111 occurs. A description oI the 193 173 inoutuc iss giveia âi. section 2.1 . A quad waveform generator (CA MAC 453) has been developed to control twelve dipole-correction element power supplies per building . The module is flexible, capable of generating waveforms for series of cycles with different energy levels and of updating waveforms at a rate of 720 Hz . A description of the 453 * Operated by Universities Research Association Inc., under contract with the US Department of Energy .
module is given in section 2.3. Other newly developed hardware pieces are the vacuum-readback interface (CAMAC 145) and status-control interface (SCI), whose descriptions are given in sections 2.2 and 2.4, respectively. Brief descriptions of other support systems (fiber-optic link, Main Ring power-supply link and Main Ring abort system) are given in sections 3.1-3 .3 . The Main Ring control system, including the frontend computer and the fiber-optic link, is shown in fig. 1.
2. New developments Z.1 The eight-channel transient recorder (CAMAC 193) The Main Ring has four magnet busses ("bend lower", "bend upper", "quad focus" and "quad defocus"). Each has a number of magnets and a number of power supplies connected in series . Voltages measured on these busses with reference to ground are monitored so that they can be properly operated and maintained. The CAMAC 193 module monitors the magnet bus voltages in three different modes ("single-channel read", "snapshot" and "transient record"). In the single-channel read mode, the host co puict can Head 6hc tnmd= stamp and the ADC data on a specified channel at its 9cistiHe. In the snapshot mode, the host specifies an arm event and a delay value. e 193 module collects data for all eight channels after the specified delay from the arm event. All the 193 modules that are distributed around the ring collect data for eight channels at the specified time. The operator can then read and plot the data on a graphic display. Such a plot enables him to
0168-9002/90/35,033 -5 0- (0 1990 - Elsevier Science Publishers B.V . (North-Holland)
VII. HARDWARE
K Seino et al. / The new Fermilab Main Ring control system
268
examine voltage distributions on the magnet busses, which allows him to locate faulty power supplies or bus ground faults. In the transient record mode, the host specifies an arm event and a number of sample triggers. The 193 module continuously collects and stores data in a circular memory buffer (2 kbytes per channel) for eight channels, and it stops the data collection at the specified number of sample triggers after the arm event. The operator can later read and plot the data from all the 193 modules around the ring. By plotting these data for different times before and after the arm event, he can tell what has happened to the magnet bus voltages as functions of time. The 193 module is double-width ; one board is a computer/ CAMAC interface which contains a Z8002 CPU, RAM, PROM, clock-event sources, interrupt controllers, a multichannel timer and a CAMAC interface . The second is a peripheral board which consists of a 10 Its 12-bit ADC subsystem and a time-stamp counter. K. Seino designed the hardware and J. Smedinghoff wrote the firmware for the 193 module [1] .
The CAMAC 145 module was designed with the Motorola MC68000 microprocessor and the MC68881 floating-point coprocessor . The serial vacuum data which come from a vacuum scanner unit are first converted to parallel, whose special BCD format is then converted to IEEE standard floating-point by the coprocessor . The module calculates an average reading from up to 63 channels off vacuum data approximately once a minute, excluding bad readings. It also generates alarms when the average vacuum value is out of limits or when 15 or more pumps are returning bad readings. Distributed intelligence to do floating-point conversion, averaging and alarm scanning was not available on the old Main Ring control system. Its addition will reduce the computational burden on the front-end computer, and the standard data format wiïl allow Main Ring vacuum devices to be placed on Eermilab's parameter pages and datalogger lists. K. Seino designed the hardware and B. Hendricks .-s?-,,e for the 145 module [2]. wrote the firm,
2.2. The vacuum-readback interface (CAMAC 145)
2.3. The quad waveform generator/ power-supply controller (CA MAC 453)
It was decided not to make extensive modifications to the entire Main Ring vacuum-control subsystem, but only to make some improvements on its readback. In this subsystem, control operations are performed via separate hardware pieces, which consist of digital input and output modules, and an SCI unit.
Main Ring operation has gradually become more complicated with the advent of the Tevatron . The accelerator is presently operated with a number of cycles, each of which may deal with a different energy level and serve a different purpose (e.g., proton acceleration, antiproton acceleration, bunch coalescing, studies, etc .).
SST SERVICE BUILDING
ACNE i
2NO SERVICE BUILDING
REPEATER REPEATER
FIBER OPTIC
LINK
FIBER WTIC LINK
REPEATER
TO 3AD BUILDING
CAMAC CRATE MR FRONT
2 B
HÎ84
T S C C
6I3I3r3
CAMAC CRATE
ACNET
VACUUM
MUX'0
SCANNER
AOC
V
PUMP
Fig. 1 . The new Fe
SIGN"
MR PS VOLT MCNIT
VULTAGE TO GFKXM SI
STATUS CONTROL INTERFACE
' . DITS
ûTATLG
DITS
MRPS
INPUT
CONTROLLER
PANEL 717
M§
"ir4 S
E8AIPA
PING
SUPPLIES
i WAa
DEMMŒ
'lab Main Ring control system including the front-end computer and the fiber-optic link .
K Seino et al. / The new Fermilab Main Ring control system
269
Fib 1. The CPU board of the CAMAC 453 quad waveforni generator module .
In order to satisfy continually changing requirements, a series of CAMAC waveform generators has been developed, starting from simple modules (160, 165 and 265), through a moderately complicated one (365), to a complicated and flexible one (453). One board of the double-width 453 module is a computer/CAMAC interface which contains an Intel 80960 microprocessor, MK PROK a TCLK (Tevatron clock) decoder, an MDAT (a link distributing accelerator parameters in real time) interface, a CAMAC interface and digital input/output circuits. The second is a peripheral board which consists of a four-channel DAC and additional digital input/output circuits . The 453 module is capable of generating four semiindependent analogue outputs at a rate of 720 Hz and of performing digital controls for up to four dipolecorrection-element power supplies. The characteristics of the anaallogue outputs. are desenibed bellow. (1) Output wavefor?ns : output = A * ml * f(t) + st * m2 * + sf3 * m3 * h(M2),
where sil, sf2 and sß are constant scale factors having a range of -128.0 to + 127 .9, ml, m.2 and m3 are raw MTEAT readings divided by 256, f(t) is an inte,7-polaied function of time and g(MI) and h(M?) are interpolated functions of the MDAT parameters .
(2) Tables : each term in the output functions has eight possible tables with up to 32 entries each. Table selection is affected by an interrupt. Sixteen interrupt the levels are available, each being awnted by "OR" of up to eight TCLK events. Upon assertion of an interrupt, the module starts using three user-specified taW; (one for each term in the output function) for each of the four output waveforms. The CPU board is densely populated, as shown in 2. In order to accommodate many functional blocks (some of them of high speed) in a limited space, the board was designed with the latest components available. Some of these are : an Intel 80960KA CPU, Fujitsu 81C78A RAMs, Cypress CY7C251 PROW Alters Eh 5032s and EPM5128s. A. Franck and J. Gomilar designed the hardware and B. Hendricks wrote the firmware for the 453 module t 3lj. 2.4. Statvs-c.° ontrol interface - the SC! unir In order to control and monitor the Main Ring magnet busses and power supplies and other support systems (vacuum, cooling and safety), a large number of digital input and output bits must be read and set . To meet this requirement, L. Anderson designed the SCI chassis, which is interfaced to the CAMAC system VIL MMWAM
270
K Seino et al. / The new Fermilab Main Ring control system
via CAMAC 186 and 284 modules. The 186 provides up to 256 bits of digital input with an external multiplexing chassis . A multiplexer card residing in the SCI decodes four address lines which originate at the 186 module, to select one of sixteen digital input channels . The 186 also provides twelve pulsed control bits, which are distributed to external devices via the SCI . The 284 module provides sixteen additional control bits which are fed to a relay box, again via the SCI . Relay contacts are used to turn on/off pumps and valves for the vacuum and water-cooling systems. The SCI consists of a 7 in x 19 in Euro-crate, Euro type-3U plug-in cards and a plug-in power-supply module. It also has a local channel select/monitor facility for digital inputs.
The active signal of the abort loop is a 5 MHz square wave, originated by the 201 module and transmitted around the ring via the fiber repeater/link system. The presence of an active signal on the abort loop, as received back by the adjacent 200 module, is interpreted as "beam permit" . The cessation of this signal, as detected there, is interpreted as "abort" . When this condition occurs, a CAMAC 279 Beam Sync clock interface/ timer module generates a trigger to abort the Main Ring beam. The CAMAC 200 modules are located in each of the 30 service buildings around the ring. They receive the upstream status of the link and provide local permits to allow the 5 MHz signal to pass downstream. CAMAC modules 200, 201 and 279 were designed by R. Ducar for Tevatron applications 16,71 .
3. Other support systems
4. Current status
3.1. Fiber-optic link
A five-month shutdown started at the end of June 1989 and the conversion of the controls has been proceeding since that time. Removal of old equipment and cables was done first; equipment-rack and cable tray installations followed . Now, at the end of October, 1989, major cables have been pulled, and a majority of hardware pieces have been installed . Most software has been completed, and testing of different subsystems is beginning . By the early part of January 1990, the entire accelerator, including the Main Ring, is expected to be operational and accelerating beam again.
Because of ever increasing demands for communication media, all 19 originally installed cables in the Main Ring/ Tevatron area are utilized. To overcome the resulting shortage and to meet requirements for future expansion, an optic trunk cable containing 24 fibers has been installed. Optic repeaters have been designed, built and installed for use with these fibers for the Main Ring CAMAC serial system, the Main Ring power-supply link and the Main Ring abort system. R. Ducar designed the fiber-optic repeaters, and the fiber-optic link was installed under his supervision . 3.2. Main Ring power-supply control system (or link)
Acknowledgements
The Main Ring power-supply system consists of a number of supplies, which energize three separate magnet busses ("bend", "quad focussing" and quad defocussing"). The power supplies are located in 15 of 24 service buildings distributed around the ring. During typical operation, the current ramps from 100 to 1700 A with a cycle time of 10 s. The control system for the Main Ring power supplies consists of two DEC PDP 11,'55 minicomputers, a link transmitter, and link receiver modules (CAMAC 269"l" The transmitter ifaû deûiped vy D . Mahler ; It 1s capable of generating 10 Mbit/s data frames and sending ramp data to all the power supplies at 720 Hz. The 269 module, designed by R. Ducar, receives ramp data : nd transmits them to the power supplies 14,51.
We wish to express our appreciation to our manager, P. Lucas, for his guidance and support . We also wish to thank R. Crouch, T. Gierhart, R. Hagler, T. Hendricks, D. Jarvis, R. Klecka and R. Koldenhoven for their hard work in constructing and installing the hardware pieces .
3.3. Main Ring abort loop The Main Ring abort loop consists of a source module (CAMAC 201), a repeater/link system and abort-concentrator modules (CAMAC 200).
References [1] K. Seino and J. Smedinghoff, Fermilab Controls Hardware Release no. 69.1 (i989) . [21 K. Seino and B. Hendricks, Fermilab Controls Hardware Release no. 70.1 (1989) . [3] A. Franck, J. Gomilar and B. Hendricks, Fermilab internal memo (1989). [4] R. Ducar and R. Mahler, Fermilab Controls Hardware Release no. 65.0 (1989). [5] R. Ducar, Fermilab Controls Hardware Release no. 66.0 (1989). rcl " rte_ ._. __ r____ ". L " N Y\. LJi1CQl, I'elllulab inter nal !91G!ήo [7]
(1982).
R. Ducar, Fermilab Controls Hardware Release no. 43.0 (1985) .