V120 RHIC Beam Permit System Module

RHIC Beam Permit Module Status

   Sextant test V120 module locations; fiberoptic routing
   Photograph V120 module
   Simplified V120  module block diagram
   PAC97 RHIC Beam Permit and Quench Detection System Communications System

Index

1.0 Introduction
1.1 Event link Interface
1.2 Permit Input Control 
1.2.1 Permit Input Control 
1.2.2 Quench Input Control 
1.3 Permit System Time Stamp Counter 
1.4 V120 Module Input/Output 
1.4.1 T120 Transition Module 
1.4.2 Rack Mounted Permit Input Chassis 
2.0 V120 Permit System Module 
2.1 Introduction 
2.2 V120 Module VME Interface 
2.2.1 VMEid (BASE ADDRESS) 
2.2.2 Control and Status Registers (BASE ADDRESS + 0x40) 
2.2.2.1 Command Register 
2.2.2.2 Status Registers
2.2.2.3 Permit Channel Enable Register
2.2.2.4 Permit Mask Status Registers 
2.2.2.5 Interrupt Control Registers 
2.2.2.6 Permit Mask Registers 
2.2.3 Word Registers (BASE ADDRESS + 0x80) 
2.2.3.1 Permit Failure Time Stamp Registers 
2.2.4 EVENT LINK Registers (BASE ADDRESS + 0x100) 
2.3 Permit System Initialization 
2.4 Implementation 
2.4.1 V120 Permit System Module 
2.4.2 T120 Transition Module 
2.4.3 T120 Rack Mounted Permit Input Strip 
3.0 Theory of Operation

1.0 INTRODUCTION

The beam permit system module design is based on RHIC requirements, and the Fermilab CAMAC 200 PERMIT CONCENTRATOR and CAMAC 201 PERMIT LINK GENERATOR. In the Fermilab CAMAC system the 201 PERMIT LINK GENERATOR (master module), contained very little logic. Thus, the permit link generator has been included beam permit concentrator module. The beam permit system module has been assigned the Accelerator Controls Section VME module number V120.

One V120 module will become beam permit/quench system master by its location, and jumper patch installed on its printed wire board. The V120 master module concentrates local beam permit inputs, and initiates a 10 MHz square wave PERMIT_LINK carrier (output or downstream). Other V120 modules receive the PERMIT_LINK carrier (input or upstream), concentrate local beam permit inputs, and retransmit the PERMIT_LINK carrier (output or downstream) - if permitted by local conditions. The PERMIT_LINK carrier returns to the master V120 module in less than 15 milliseconds (if all beam permit system inputs are enabled). When the master V120 module detects carrier at its upstream input, beam is permitted in the RHIC rings.

During the first loop around the RHIC ring, the fiber optic link receivers require approximately 8 msec to detect carrier, and unblank. As there may be 40-50 fiber optic links around the RHIC ring, there is an initial permit/quench link loop delay of 300-400 msec. Once each fiber optic has unblanked, the fiber optic, copper wire, and integrated circuit propagation delays will not exceed 2 beam revolutions.

After the PERMIT_LINK is established, any V120 module detecting a permit, or upstream PERMIT_LINK carrier failure terminates its local permit level and PERMIT_LINK carrier outputs. The PERMIT_LINK carrier failure propagates around the RHIC ring, terminating local permit level and PERMIT_LINK carrier outputs. When the V120 master module detects an upstream PERMIT_LINK carrier failure, its local permit level and PERMIT_LINK carrier outputs, blue and yellow beam dump commands are initiated, and an abort event code is triggered. The PERMIT_LINK carrier failure continues to propagate from the master module to the module that initiated the failure, terminating local permit levels and PERMIT_LINK carrier outputs. Thus, within two beam revolutions, all V120 modules have detected the failure, the beam dump initiated, and local permit levels terminated.

Note: If QUENCH system is enabled, a BLUE or YELLOW QUENCH_LINK carrier failure, or a quench input failure will terminate the PERMIT_LINK carrier. [(Added 3/22/02-EdK) This is the normal mode for machine operations. The logic in the ALTERA chips was modified so that the QUENCH inputs can now be disabled, when disabled the corresponding QUENCH link will fail but not the PERMIT link. This modification was made to allow power supply testing with only one ring up and running.]

The RHIC beam permit system modules also contains the power supply interlock system. There are separate blue and yellow magnet quench detection systems. Two of the V120 module permit inputs are reserved for blue and yellow magnet quench detection system outputs. These two inputs trigger both a beam dump, and power supply emergency shutdown. However, a magnet quench detection in one beam line will not effect the power supplies in the other beam line.

The V120 master module initiates two magnet power supply QUENCH_LINK carriers (blue and yellow). The QUENCH_LINK carriers are controlled by the two beam permit inputs reserved for the quench detection system outputs. [(Added 3/22/02-EdK) The QUENCH inputs can now be disabled by software, when disabled the QUENCH link will still fail but the PERMIT will not. The sequencer should check these settings before the start of beam operations.] The V120 master module initiates the QUENCH_LINK carriers (output or downstream) if the quench inputs are valid. Other V120 modules receive the QUENCH_LINK carriers (input or upstream), and retransmit the QUENCH_LINK carrier (output or downstream) - if permitted by local conditions. The QUENCH_LINK carriers return to the master V120 module in less than 15 milliseconds (if all quench inputs are enabled). As the QUENCH_LINK carriers propagate around the RHIC ring, local blue and yellow power supply interlock levels are initiated.

After the QUENCH_LINK is established, [3/22/02-in normal operation, QUENCH inputs enabled,] any V120 module detecting a quench input failure, or upstream QUENCH_LINK carrier failure terminates the appropriate local power supply interlock, QUENCH_LINK carrier, and PERMIT_LINK carrier. The QUENCH_LINK carrier failure propagates around the RHIC ring, terminating appropriate local power supply interlocks and QUENCH_LINK carrier outputs. When the V120 master module detects an upstream QUENCH_LINK carrier failure, its appropriate local power supply interlock level and QUENCH_LINK carrier outputs are terminated. At approximately the same time the V120 master module would detect a PERMIT_LINK failure, and dump the beam. The QUENCH_LINK carrier failure continues to propagate from the master module to the module that initiated the failure, terminating appropriate local power supply interlock levels and QUENCH_LINK carrier outputs. Thus, within two beam revolutions, all V120 modules have detected the failure, appropriate local power supply interlock levels terminated. In addition the interconnection of the quench and permit will initiated a beam dump, and terminate local permit levels.

If a permit system failure is not caused by a quench system failure, the PERMIT_LINK failure - beam dump will not effect the quench links. The QUENCH_LINK carriers, and local power supply interlocks are not affected.

The V120 permit system module input/output characteristics are:

• Six (6) positive true, fail-safe permit inputs, driver must provide a TTL level into 50 ohms termination. Permit inputs may be activated/deactivated by VMEbus command, and may be masked during operation by event code commands.
• Two (2) positive true, fail-safe quench inputs, driver must provide a TTL level into 50 ohms termination. Quench inputs can't be deactivated by VMEbus command or masked by event code command. [(Added 3/22/02-EdK) They can be disabled so that they will not pull the PERMIT link but this mode should only be used during testing.] Quench inputs can be permanently deactivated by jumper patch on the V120 module.
• Three (3) 10 MHz carrier inputs, on-off modulation; permit, blue quench, and yellow quench links. Driver must drive differential TTL line. Input is transformer coupled for galvanic isolation, and terminated in 100 ohms. Connecting wire is shielded twisted pair, with shield connected to VME chassis ground at V120 module. These links are point-to-point, not party line.
• One (1) 10 MHz carrier, bi-phase-mark modulated input event link. Driver must drive differential TTL line. Input is transformer coupled for galvanic isolation, and terminated in 100 ohms. Connecting wire is shielded twisted pair, with shield connected to VME chassis ground at V120 module. These links are point-to-point, not party line.
• Three (3) 10 MHz carrier outputs, on-off modulation; permit, blue quench, and yellow quench links. Driver output differential TTL. Driver expects transformer isolation, and 100 ohm termination at receiver. Driver expects a single receiver, not a party line. Connecting wire is shielded twisted pair, with shield connected to VME chassis ground at V120 module.
• One (1) positive true, fail-safe, level output, local permit level. Driver provides a minimum pulse amplitude of 3.0 volts into 50 ohms termination. The permit output is at GROUND level on initialization (RPR - event code reset permit registers). The local permit level will rise to 3.0 volts after the PERMIT_LINK has been established - approximately 15 milliseconds after initialization. After initialization, the local permit level will fall to GROUND to indicate a permit system failure.
• Two (2) positive true, fail-safe, level outputs, blue power supply interlock, and yellow power supply interlock. Driver provides a minimum pulse amplitude of 3.0 volts into 50 ohms termination. There are separate blue and yellow power supply quench detector systems, therefore each power supply quench link operates independently. The interlock outputs are at GROUND on initialization (RQR - event code reset quench registers). The interlock outputs rise to 3.0 volts approximately 15 milliseconds after initialization. After initialization, an interlock output will fall to GROUND to indicate a quench input failure. The permit system beam dump commands do not effect the power supply interlock, unless the beam dump was caused by a magnet quench.

The quench system may be disabled, creating an 8-input permit system module.

The three V120 module carrier outputs are differential TTL, transmitted over shielded, twin-axial, copper cable. The three V120 module carrier inputs are transformer coupled for galvanic isolation. Twin-axial cable transmission is used between V120 modules in close proximity: <25 meters. For long distance transmission, between equipment houses, fiber optic transmission is used. Standard RHIC dual channel TTL/fiber optic transmitter and receivers are used to transmit the permit/quench carriers.

Each V120 module contains a total of 8 fail-safe inputs: 6 permit and 2 quench inputs. The equipment driving the inputs must be capable of supplying 40-50 ma into 50 ohm, termination. The inputs are referenced to the module VME chassis ground, and isolated from the logic digital ground by optoisolators.

If a permit or quench input is lost due to equipment or cable connection failure the V120 module will:

1. Terminate the downstream PERMIT_LINK carrier output.
2. Log the permit or quench input's time of failure.
3. Generate a VMEbus interrupt (if enabled).
4. Log other permit or quench input's time of failure.
5. Log the upstream PERMIT_LINK carrier failure time.
6. If its a quench input, the appropriate downstream QUENCH_LINK carrier, and local power supply interlock will terminated.

1. Terminate the downstream PERMIT_LINK carrier output.
2. Log the upstream PERMIT_LINK carrier failure time.
3. Generate a VMEbus interrupt (if enabled).
4. Terminate the local permit level output.
5. Log any local permit or quench input's time of failure.

1. Terminate the appropriate QUENCH_LINK carrier downstream output.
2. Log the upstream QUENCH_LINK carrier failure time.
3. Terminate the appropriate local power supply interlock output.
4. Generate a VMEbus interrupt (if enabled).
5. Log any local permit or quench input's time of failure.

If the V120 is the master module, in addition to PERMIT_LINK carrier failure logging functions, an upstream carrier failure will:

1. Terminate the PERMIT_LINK carrier generator.
2. Immediately generate the RHIC EVENT_LINK abort event code trigger.

1. Terminate the appropriate QUENCH_LINK carrier generator.
2. Terminate the appropriate local power supply interlock output.

1.1 Event Link Interface

1. pulse RPR: reset PERMIT registers, and initialize the permit link
2. pulse RQR: reset QUENCH registers, and initialize the blue and yellow quench links
3. pulse RTC: reset TIME STAMP counter
4. SET: set mask register to value of SM[2..0], and enable mask
5. RST: disable mask
6. SM0 \
7. SM1 | = mask code: 0-7 valid
8. SM2 /

The 256-byte event code translation table is stored in a SRAM. The SRAM is memory mapped on the VMEbus as 256 byte, read/write, registers.

1.2 Permit and Quench Input Control

1.2.1 Permit Input Control

Eight bit-encoded mask registers may be enabled, one at a time, to temporally disable permit inputs. The masks are selected and enabled by an EVENT_LINK event codes (paragraph 1.1 above). A permit input mask is terminated by an EVENT_LINK event code that disables the current mask, or an event code that selects and enables another mask. When a masked permit input fails, the time-of-failure is logged. However, the failure does not initiate a beam dump! The failure does generate a VMEbus interrupt (if enabled).

When a V120 module permit input fails, a latch is set. The latch holds a transient input failure until it can be reported to the front end computer. The module input failure logic is an OR of the input and its latch. The input failure latch is reset by a VMEbus register read, or by EVENT_LINK event code reset PERMIT registers (RPR). When the permit latch is reset, its time stamp register is cleared.

WARNING: A masked, transient, permit input failure must be cleared before the mask terminates. If the permit failure latch is not cleared, a beam dump command will be initiated as the mask terminates!

1.2.2 Quench Input Control

When a V120 module quench input fails, a latch is set. The latch holds a transient input failure until it can be reported to the front end computer. The module input failure logic is an OR of the input and its latch. The input failure latch is reset by a VMEbus register read, or by EVENT_LINK event code reset QUENCH registers (RQR). When the quench latch is reset, its time stamp register is cleared.

1.3 Permit System Time Stamp Counter

Note: The V120 module EVENT_LINK decoder is based on an AT&T clock and data recovery circuit. The circuit PLL will drift to center frequency (10.062 MHz, 0.0994 usec) on EVENT_LINK failure. This will maintain time stamp activity during a EVENT_LINK failure.

1.4 V120 Module Input/Output

1.4.1 T120 Transition Module

1.4.2 Rack Mounted Permit Input Strip

2.0 V120 PERMIT SYSTEM MODULE

2.1 Introduction

V120 block diagram.

2.1.1 V120 Permit System Module Front Panel

The V120 Permit System Module Front Panel contains the EVENT LINK input. All other connections to the V120 permit system module are made on the T120 transition module and rack mounted permit input chassis. The front panel indicators are:

    Green indicator LEDs
      VME SEL   VME SELECT               V120 module addressed by VME bus
      MASTER    MASTER                   V120 module is MASTER module
      EVENTLNK  EVENT LINK               RHIC timeline carrier detected
      BLUINDEX                           UNUSED 
      YELINDEX                           UNUSED
      BLINTLNK  BLUE INTERLOCK LINK      Blue power supply interlock link carrier detected
      YEINTLNK  YELLOW INTERLOCK LINK    Yellow power supply interlock link carrier detected
      PERMIT 1  PERMIT INPUT 1           Permit input is active, or disabled by software
      PERMIT 2  PERMIT INPUT 2           Permit input is active, or disabled by software
      PERMIT 3  PERMIT INPUT 3           Permit input is active, or disabled by software
      PERMIT 4  PERMIT INPUT 4           Permit input is active, or disabled by software
      PERMIT 5  PERMIT INPUT 5           Permit input is active, or disabled by software
      PERMIT 6  PERMIT INPUT 6           Permit input is active, or disabled by software
      QUENCH 7  QUENCH INPUT 7           Quench input is active, or disabled by jumper patch
      QUENCH 8  QUENCH INPUT 8           Quench input is active, or disabled by jumper patch
    Red indicator LEDs
      OFFLINE   OFFLINE                  V120 module is non-functional
      BEAM DUMP BEAM DUMP                Beam dump conditions detected
      BLU DUMP                           UNUSED 
      YEL DUMP                           UNUSED
      B PS LINK BLUE POWER SUPPLY LINK   Blue power supply interlock failed 
      Y PS LINK YELLOW POWER SUPPLY LINK Yellow power supply interlock failed
      SPARE     unassigned
      SPARE     unassigned

2.2 V120 Module VME Interface

|MSB____________A16 ADDRESS SPACE____________LSB|
|15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00|
|----BASE-ADDRESS----| 0  0  0  X  X  X  X  X  X| VME status/ID PROM(byte)
       (PATCH)       | 0  0  1  0  0  X  X  X  X| byte registers 
                     | 0  1  0  0  X  X  X  X  X| byte/word registers
                     | 1  X  X  X  X  X  X  X  X| event code SRAM(byte)

2.2.1 VMEid (BASE ADDRESS)

2.2.2 Control and Status Registers (BASE ADDRESS + 0x40)

_____________|MSB________________________ LSB|
_____________| X | X | X | X | X | X | X | X | BASE + 0x40 (unused)
COMMAND_REG1_| 0 | 0 | 0 | 0 | 0 |DMP|INT|ENA| BASE + 0x41 (read/write)
STATUS_REG0__|PCF|MST|ECF|PTY| X | X |YQF|BQF| BASE + 0x42 (read only)
STATUS_REG1__|QI8|QI7|PI6|PI5|PI4|PI3|PI2|PI1| BASE + 0x43 (read only)
CHAN_ENA_REG_| E8| E6| E6| E5| E4| E3| E2| E1| BASE + 0x44 (read/write)
STATUS_MASK__|QJS| X | X | X |MSK|SM2|SM1|SM0| BASE + 0x45 (read only)
INT_VEC_REG__| V7| V6| V5| V4| V3| V2| V1| V0| BASE + 0x46 (read/write)
INT_LEV_REG__| 0 | 0 | 0 | 0 | 0 | L2| L1| L0| BASE + 0x47 (read/write)
PERMIT_MASK0_| X | X | P6| P5| P4| P3| P2| P1| BASE + 0x48 (read/write)
PERMIT_MASK1_| X | X | P6| P5| P4| P3| P2| P1| BASE + 0x49 (read/write)
PERMIT_MASK2_| X | X | P6| P5| P4| P3| P2| P1| BASE + 0x4A (read/write)
PERMIT_MASK3_| X | X | P6| P5| P4| P3| P2| P1| BASE + 0x4B (read/write)
PERMIT_MASK4_| X | X | P6| P5| P4| P3| P2| P1| BASE + 0x4C (read/write)
PERMIT_MASK5_| X | X | P6| P5| P4| P3| P2| P1| BASE + 0x4D (read/write)
PERMIT_MASK6_| X | X | P6| P5| P4| P3| P2| P1| BASE + 0x4E (read/write)
PERMIT_MASK7_| X | X | P6| P5| P4| P3| P2| P1| BASE + 0x4F (read/write)

2.2.2.1 Command Registers

If the ENAble bit is reset, the V120 module is inactive - can't output permit or quench carriers, or local permit or interlock levels . If the ENAble bit is set, the V120 module functions depend upon the state of module jumper patches, other registers, and previous EVENT_LINK event codes.

The INTerrupt bit enables the V120 module interrupt. An interrupt is generated if any STATUS_REG input changes state. The change-of-state interrupt includes both states of an interrupt. A bad-to-good change-of-state will cause an interrupt as will a good-to-bad change-of-state.

In the master V120 module, setting COMMAND_REG1 DuMP initiates an immediate beam dump. The DMP bit must be reset to restart the permit system. The DMP bit does not effect the quench carriers.

2.2.2.2 Status Registers

The first byte of the status register, STATUS_REG0, indicates the operating status of the V120 module permit and quench carriers. The STATUS_REG0 bits are shown in the table below:

1. PCF = Upstream PERMIT_LINK input carrier failed
2. MST = Module is MASTER V120 module
3. TCF = EVENT_LINK carrier failed
4. PTY = EVENT_LINK event code parity/framing error detected
5. YQF = YELLOW_QUENCH_LINK carrier failed
6. BQF = BLUE_QUENCH_LINK carrier failed

1. PF1 = PERMIT_INPUT 1 failed
2. PF2 = PERMIT_INPUT 2 failed
3. PF3 = PERMIT_INPUT 3 failed
4. PF4 = PERMIT_INPUT 4 failed
5. PF5 = PERMIT_INPUT 5 failed
6. PF6 = PERMIT_INPUT 6 failed
7. QF7 = QUENCH_INPUT 7 failed
8. QF8 = QUENCH_INPUT 8 failed

2.2.2.3 Permit Channel Enable Register

The sense of this register is inverted: zero = enable; one = disable. Therefore, on initialization all permit input channels are enabled. Permit channels are disabled by writing a one into the appropriate bit position.

NOTE: The CHAN_ENA_REG register doesn't effect the 2 quench inputs. The quench inputs are active until deactivated by jumper patches on the V120 module.[(Added 3/25/02-EdK) A modification was made that now changes this. The QUENCH inputs can now be ENABLED or DISABLED, when ENABLED the input will affect the PERMIT link, when DISABLED the QUENCH link will drop but not affect the PERMIT link. This was added to allow testing of either yellow or blue rings during non-beam periods. During normal operations the QUENCH inputs should always be enabled.]

2.2.2.4 Permit Mask Status Register

1. SMO = LSB permit mask select register
2. SM1
3. SM2 = MSB permit mask select register
4. MSK = selected mask is active.
5. 0
6. 0
7. 0
8. QJS = Quench Jumper Status

2.2.2.5 Interrupt Control Registers

2.2.2.6 Permit Mask Registers

NOTE: The PERMIT_MASK[x] registers don't effect the 2 quench inputs. The quench inputs can't be masked. [ Added 3/25/02-EdK-If the board is jumpered as an 8 input permit module then the mask will work on all 8 inputs.]

WARNING: The front end computer must respond to the masked failures before the mask terminates. If the latched masked failure is not cleared, a permit failure will cause a beam dump as the mask terminates.

2.2.3 Time Stamp Word Registers (BASE ADDRESS + 0x80)

Three additional time stamp registers contain the contents of the time stamp counter when the V120 module determined that the respective upstream carrier input failed.

NOTE: The byte mode access was added for compatibility with the VxWorks shell. The register display command operates in the byte mode. DO NOT USE the byte mode to read the registers, except when using the VxWorks shell. The byte mode reads the 32-bit time stamp register as four bytes. On the third byte read the automatic register reset is enabled. Therefore, the fourth byte will always be 0x00 in the byte mode.

_____________ |MSB_________________________________________LSB|
PERMIT_FAIL_0 |31|30|29|28|27|26|25|24|23|22|21|21|19|18|17|16| BASE + 0x80 (read only)
_____________ |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00| BASE + 0x82 (read only)
PERMIT_FAIL_1 |31|30|29|28|27|26|25|24|23|22|21|21|19|18|17|16| BASE + 0x84 (read only)
_____________ |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00| BASE + 0x86 (read only)
PERMIT_FAIL_2 |31|30|29|28|27|26|25|24|23|22|21|21|19|18|17|16| BASE + 0x88 (read only)
_____________ |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00| BASE + 0x8a (read only)
PERMIT_FAIL_3 |31|30|29|28|27|26|25|24|23|22|21|21|19|18|17|16| BASE + 0x8c (read only)
_____________ |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00| BASE + 0x8e (read only)
PERMIT_FAIL_4 |31|30|29|28|27|26|25|24|23|22|21|21|19|18|17|16| BASE + 0x90 (read only)
_____________ |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00| BASE + 0x92 (read only)
PERMIT_FAIL_5 | X| X| X| X| X| X| X| X|23|22|21|21|19|18|17|16| BASE + 0x94 (read only)
_____________ |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00| BASE + 0x96 (read only)
QUENCH_FAIL_6 | X| X| X| X| X| X| X| X|23|22|21|21|19|18|17|16| BASE + 0x98 (read only)
_____________ |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00| BASE + 0x9a (read only)
QUENCH_FAIL_7 | X| X| X| X| X| X| X| X|23|22|21|21|19|18|17|16| BASE + 0x9c (read only)
_____________ |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00| BASE + 0x9e (read only)
UPSTREAM_FAIL | X| X| X| X| X| X| X| X|23|22|21|21|19|18|17|16| BASE + 0xa0 (read only)
_____________ |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00| BASE + 0xa2 (read only)
BLU_UPSTR_FAIL| X| X| X| X| X| X| X| X|23|22|21|21|19|18|17|16| BASE + 0xb0 (read only)
_____________ |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00| BASE + 0xb2 (read only)
YEL_UPSTR_FAIL| X| X| X| X| X| X| X| X|23|22|21|21|19|18|17|16| BASE + 0xb4 (read only)
_____________ |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00| BASE + 0xb6 (read only) 

2.2.4 EVENT LINK Registers (BASE ADDRESS + 0x100)

_____________|MSB_________________________LSB|
EVENT_CODE_00|SM2|SM1|SM0|RST|SET|RTC|RQR|RPR|
EVENT_CODE_01|SM2|SM1|SM0|RST|SET|RTC|RQR|RPR|
                   "
                   "
EVENT_CODE_FE|SM2|SM1|SM0|RST|SET|RTC|RQR|RPR|
EVENT_CODE_FF|SM2|SM1|SM0|RST|SET|RTC|RQR|RPR|
where:

1. RPR = reset PERMIT registers
2. RQR = reset QUENCH registers
3. RTC = reset TIME STAMP counter
4. SET = set mask register to value of SM[2..0], and enable mask
5. RST = disable mask
6. SM0 \
7. SM1 | = permit mask code
8. SM2 /

2.3 Permit System Initialization

1. Install the master module jumper patch
2. Install module in the master module VME chassis.
3. Connect PERMIT_LINK upstream/downstream cables
4. Connect BLUE & YELLOW QUENCH_LINK upstream/downstream cables.
5. Connect the local blue & yellow power supply interlock cables.
6. Connect EVENT_LINK cable.
7. Connect local permit and quench inputs.

1. Check that the module master jumper patch is removed.
2. Install module in a slave module VME chassis.
3. Connect PERMIT_LINK upstream/downstream cables
4. Connect BLUE & YELLOW QUENCH_LINK upstream/downstream cables.
5. Connect the local blue & yellow power supply interlock cables.
6. Connect EVENT_LINK cable.
7. Connect local permit and quench inputs.

1. The V120 permit system module is not affected by VME chassis SYSRESET* which is generated at primary power on, VME chassis reset button, commanded by the front end computer, or commanded by the V108 Utility module. The V120 permit system module does not respond to SYSRESET* to maintain the power supply QUENCH_LINK when the VME chassis is reset by the V108 Utility module. The V120 module will be inactive when the VME chassis primary power is applied. Once power is applied, the V120 module state depends upon last front end computer command, and external inputs. Initially the front end computer must load the permit enable (1),interrupt (2), mask (8), and event code (256) registers, and then command register (1).
2. V120 modules will be enabled (ENAble set) at various times by their VME chassis front end computers. As each V120 module is enabled, it will detect a PERMIT_LINK carrier failure, and possibly permit input failures. The V120 module will time stamp the failures, and attempt to interrupt its front end computer. If an active permit, or quench input has failed to activate, the module can't pass the PERMIT_LINK carrier until failure(s) is corrected. In addition, if a quench input has failed to activate, the module can't pass the appropriate QUENCH_LINK carrier until the quench input failure is corrected.
3. The control room can issue a network inquiry to check permit and quench inputs before attempting to initiate the permit system.
4. The control room should assure that a RHIC EVENT_LINK event code RTC (reset time stamp counters) has been transmitted to synchronize the V120 module time stamp counters
5. To initiate the BLUE & YELLOW QUENCH_LINKS the control room issues event code, RQR (reset quench registers) to clear latched quench input failures, and activate the carrier activation time delay (approximately 15 milliseconds). In the master module, the BLUE & YELLOW QUENCH_LINK carriers are initiated. The time delay allows the QUENCH_LINK carriers to propagate around the RHIC ring, through all the V120 modules, and return to the master V120 module. When the delay is completed, all V120 modules activate their local blue & yellow power supply interlock outputs if the QUENCH_LINK is established.
6. To initiate the PERMIT_LINK the control room issues event code, RPR (reset permit registers) to clear latched permit input failures, and activate the carrier activation time delay (approximately 15 milliseconds). In the master module, the PERMIT_LINK carrier is initiated. The time delay allows the PERMIT_LINK carrier to propagate around the RHIC ring, through all the V120 modules, and return to the master V120 module. When the delay is completed, all V120 modules activate their local permit level outputs if the PERMIT_LINK is established.
7. After the V120 master module permit time delay is complete, a PERMIT_LINK carrier failure will terminate the PERMIT_LINK carrier output and cause a beam dump.
8. After the V120 master module quench time delay is complete, a QUENCH_LINK carrier failure will terminate the appropriate color QUENCH_LINK carrier and local power supply interlock output.
9. While the permit system is active, V120 master and slave module permit input failures may be masked. A masked permit input failure will latch, time stamp, and generate a VMEbus interrupt (if enabled). The permit input failure must be cleared before the mask terminates. If not cleared, the permit input failure latch will cause a beam dump as the mask clears!
10. While the permit system is active, V120 master and slave module quench input failures can't be masked. A quench input failure will always cause a beam dump sequence, and appropriate color QUENCH_LINK carrier and local power supply interlock termination.[(Added 3/25/02-EdK) A modification was made that now changes this. The QUENCH inputs can now be ENABLED or DISABLED, when ENABLED the input will affect the PERMIT link, when DISABLED the QUENCH link will drop but not affect the PERMIT link. This was added to allow testing of either yellow or blue rings during non-beam periods. During normal operations the QUENCH inputs should always be enabled.]
11. A RHIC EVENT_LINK event code RTC (reset time stamp counters) should be transmitted at least once an hour to resynchronize the V120 module time stamp counters.

2.4 Implementation

2.4.1 V120 Permit System Module

The Altera MAX9000 family allows ISP (in-circuit-programming), and JTAG (boundary scan testing). The V120 printed wiring board will be designed for ISP as it is required to program the surface mount packages. The wiring will also allow JTAG development in the future.

1. The first EPLD holds the VMEbus interface, registers, EVENT_LINK decoder, and permit carrier detection logic.
2. The second EPLD contains four permit input conditioners, a 32-bit time stamp counter, and five 32-bit registers to time stamp four permit inputs, and the upstream PERMIT_LINK carrier time-of-failure. This EPLD also contains the beam dump logic.
3. The third EPLD contains two permit and two quench input conditioners, a 32-bit time stamp counter, and four 32-bit registers to time stamp the permit and quench inputs time-of-failure. This EPLD also contains the BLUE & YELLOW QUENCH_LINK and local power supply interlock logic.

• 3 208-pin SM EPLDs
• 1 DIP VMEid PROM
• 1 DIP 2Kx8 SRAM
• 12 DIP integrated circuits
• 10 DIP optoisolator integrated circuits to isolate the T120 module single ended inputs
• 1 DIP integrated circuit AT&T clock recovery circuit
• 16 front panel indicator LEDs.

2.4.2 T120 Transition Module

2.4.3 T120 Rack Mounted Permit Input  Strip