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46.1 GENERAL . . . . . . . . . . . . . . . . . . . . 46-1

46.2 SERIAL LINE PROTOCOL . . . . . . . . . . . . . . 46-1

46.2.1 Commands (From Driver to SCC) . . . . . . . . 46-1

46.2.2 Responses (From SCC to Driver) . . . . . . . . 46-2

46.2.3 Sync, Termination, Biphase Modulation . . . . 46-3

46.2.4 Mode of Operations . . . . . . . . . . . . . . 46-3

46.3 CODING FORMATS FOR SCC . . . . . . . . . . . . . 46-3

46.3.1 Line Control Bits . . . . . . . . . . . . . . 46-3

46.3.2 CAMAC Function Codes . . . . . . . . . . . . . 46-4

46.3.3 Special Commands of the SCC . . . . . . . . . 46-4

46.4 POWER ON CONDITION . . . . . . . . . . . . . . . 46-5

46.5 TIMING PARAMETERS . . . . . . . . . . . . . . . 46-5

46.6 CONNECTORS AND TERMINATORS . . . . . . . . . . . 46-5

46.6.1 Front Panel Connectors . . . . . . . . . . . . 46-5

46.6.2 Terminators . . . . . . . . . . . . . . . . . 46-6

46.7 FRONT PANEL . . . . . . . . . . . . . . . . . . 46-6

46.8 AUXILIARY CONTROLLERS AND LAM HANDLING . . . . . 46-6

46.9 POWER AND TEMPERATURE . . . . . . . . . . . . . 46-6

46.10 POWER REQUIREMENT: . . . . . . . . . . . . . . . 46-7

46.11 OPERATING TEMPERATURE RANGE . . . . . . . . . . 46-7

46.12 DRAWING PACKAGE NUMBER . . . . . . . . . . . . . 46-7

46.13 RESPONSIBLE ENGINEER . . . . . . . . . . . . . . 46-7 CHAPTER 46 SLC SERIAL CRATE CONTROLLER (SCC)

46.1 GENERAL This is a double width CAMAC crate controller meeting the CAMAC standards. It was designed especially for the SLC Control System, but there are other applications where the cabling advantages of serial transmission are desired. Serial signal transmission is biphase, signal levels are RS-422, and up to 16 crate controllers can be run on a single twisted pair. An additional pair is required for immediate L response from crates. Normally the line is driven by a "Multibus CAMAC Driver," MBCD, but other drivers are available. The data transmission bit rate is nominally 5 Megabits/sec, but this can be changed easily with plug-ins. Line lengths of up to 500 feet have been run at 5 Megabits/sec., using Belden 9730, and up to 1000 feet using Belden 9851.

46.2 SERIAL LINE PROTOCOL The protocol is defined by a special sync bit, followed by 3 line control bits, the command or data message, and completed by a terminator. ----------------- |SABC|(message)|T |Y | | |N | | |C | |

46.2.1 Commands (From Driver to SCC) ______________________________ This chapter is excerpted from ELLDOC #18, SLC SERIAL CRATE CONTROLLER (SCC).


SLC SERIAL CRATE CONTROLLER (SCC) Page 46-2

46.2.1.1 CAMAC Command - 00X | | | | | ABCC|CCCF|FFFF|MMMM|MAAA|A ----|----|----|----|----|---- 1|2481|2481|1248|1124|8 | | 6| |6 | Note: Crate number runs from 0 to 15 as set on front panel thumbwheel switch. Module number runs from 1 to 23 in standard CAMAC fashion; N=31 addresses all modules in given crate.

46.2.1.2 Write Data - 16 Bits or 24 Bits - 010 | | | | | | ----|----|----|----|----|----|---- ABCW|WWWW|WWWW|WWWW|WWWW|WWWW|WWW 1|2345|6789|1111|1111|1122|222 | | |0123|4567|8901|234 Bits W17-W24 are optional for 24 bit transfers.

46.2.1.3 Short Command for Read Block Transfer, or Repeat Control: - |011 |---- |ABC

46.2.2 Responses (From SCC to Driver)

46.2.2.1 Read Data - 16 Bits or 24 Bits - 10X | | | | | | | ----|----|----|----|----|----|----|---- ABCQ|XLRR|RRRR|RRRR|RRRR|RRRR|RRRR|RR | 12|3456|7891|1111|1111|1222|22 | | | 0|1234|5678|9012|34 L="or" of L lines in addressed crate, gated by L enable.

46.2.2.2 Read L Lines - 24 Bit Mode - 101 | | | | | | | ----|----|----|----|----|----|----|---- ABCI|*LLL|LLLL|LLLL|LLLL|LLLL|LLLL|LL | 12|3456|7891|1111|1111|1222|22 | | | 0|1234|5678|9012|34


SLC SERIAL CRATE CONTROLLER (SCC) Page 46-3 * Reads state of L Enable F-F

46.2.2.3 Short Response for Write, Write Block Transfer, Control - 111 | ----|---- ABCQ|XL

46.2.3 Sync, Termination, Biphase Modulation Sync is always a positive line level (1 state) two clock periods long (400 nanoseconds). Termination consists of return to logical zero after 100 nanoseconds if line ends in "1" state at end of message. In the quiescent state, the line is normally held at the zero level prior to the sync. In biphase modulations there is a transition at each bit boundary, with a "1" indicated by the transition in the center, a "0" has no transition.

46.2.4 Mode of Operations A crate controller once addressed remains in this state until another one on the line is addressed using a CAMAC command. Control bit C selects 16 or 24 bit mode. The crate controller remains in the selected mode until re-addressed. The crate controller can implement only SINGLE ADDRESS block transfers. The driver must check Q and/or X to deal with termination or a word counter must be used. There is a defined response after every operation except after a WRITE command. Write data may follow immediately after the WRITE command. Strings of WRITE data indicate a write block transfer.

46.3 CODING FORMATS FOR SCC

46.3.1 Line Control Bits ABC LINE USAGE ___ __________ 000 COMMAND - CNAF - 16 BIT MODE FOR READ/WRITE 001 COMMAND - CNAF - 24 BIT MODE FOR READ/WRITE


SLC SERIAL CRATE CONTROLLER (SCC) Page 46-4 010 COMMAND - WRITE DATA 011 COMMAND - SHORT COMMAND FOR READ OR CONTROL BLOCK TRANSFER 100 RESPONSE - READ DATA - 16 BIT MODE 101 RESPONSE - READ DATA - 24 BIT MODE 110 RESPONSE - NOT USED 111 RESPONSE - SHORT RESPONSE FOR WRITE, WRITE BLOCK TRANSFER, CONTROL, AND CONTROL BLOCK TRANSFER

46.3.2 CAMAC Function Codes F0 - F7 READ COMMANDS - USING R LINES F8 - F15 CONTROL COMMANDS F16- F23 WRITE COMMANDS - USING W LINES F24- F31 CONTROL COMMANDS These commands and terminology are in accordance with the CAMAC Standard, and primarily refer to line usage in the CAMAC Crate.

46.3.3 Special Commands of the SCC N31 : ALL MODULES N30 F0 A0-7: READ L SIGNALS, I LINE, L ENABLE N30 F24 A9 : SET I = 0; RESPONSE Q=0, X=0 N30 F26 A9 : SET I = 1; RESPONSE Q=0, X=0 N30 F24 A10 : DISABLE OVERALL L IN CRATE; RESPONSE Q=0, X=0 N30 F26 A10 : ENABLE OVERALL L IN CRATE; RESPONSE Q=0, X=0 N28 F26 A9 : RUN CYCLE WITH C=1, RESPONSE Q=0, X=0 N28 F26 A8 : RUN CYCLE WITH Z=1, SET I=0, DISABLE L


SLC SERIAL CRATE CONTROLLER (SCC) Page 46-5

46.4 POWER ON CONDITION When power is first turned on, the SCC is in the unaddressed state I=0, and L is Disabled, the same as after a Z command as indicated. It is recommended that a Z operation be performed to clear the modules in the crate after power turn on.

46.5 TIMING PARAMETERS At 5 Megabits/second the CAMAC cycle time is 1.2 microseconds long, with 200 nanosecond pulses for S1 and S2. "Busy" B is generated for the 1.2 microsecond CAMAC cycle, and the command lines are only active during the CAMAC cycle. At the given bit rate the total operating times are as follows, for 16 bit operations: o READ: 11 microseconds per word. o WRITE: 12 microseconds per word. o CONTROL: 8 microseconds per word. o READ BLOCK TRANSFER:

7.5 microseconds per word. o CONTROL BLOCK tRANSFER:

4.5 microseconds per word.

46.6 CONNECTORS AND TERMINATORS

46.6.1 Front Panel Connectors Two MS3120E-10-6S bussed together A Signal Data + B Signal Data - C L+ (OR of all enabled crate L's) D L- E Ground F +5 Volts


SLC SERIAL CRATE CONTROLLER (SCC) Page 46-6

46.6.2 Terminators For proper operation it is required that both ends of the line be terminated.

46.7 FRONT PANEL The thumbwheel switch sets crate address 0-15 DECIMAL. The Inhibit connector sets I=1 on the dataway when the level is 0V, and I=0 when the level is TTL high or open. This is an OR function with the internal operation. The clear connector generates C=1 and S2=1 on the dataway when the level is 0V. This is an OR function with the internal operation. Indicators are as follows: o Crate Addressed: Indicates this controller is in addressed mode. o Busy: Running a CAMAC cycle. This indicator has a one-shot on it. o L Enable: Indicates state of the L Enable flip-flop. o L: Indicates overall OR of L lines in the crate gated with L Enable. o I: Indicates state of I line

46.8 AUXILIARY CONTROLLERS AND LAM HANDLING A rear panel printed circuit connector permits use of additional controllers in the crate when the SCC is not busy in the crate. No handshake timing is provided, and the auxiliary controller must get off the bus immediately when busy=1. Refer to the schematic 135-559 for the necessary pin connections, levels, and current requirements. This rear panel connector also provides access to the state of 23 L lines in the crate for special LAM handling facilities as desired.

46.9 POWER AND TEMPERATURE


SLC SERIAL CRATE CONTROLLER (SCC) Page 46-7

46.10 POWER REQUIREMENT: +6 Volts @ l.6 Amps +24 Volts @ 17 milliAmps

46.11 OPERATING TEMPERATURE RANGE 0 degrees - 60 degrees Celsius.

46.12 DRAWING PACKAGE NUMBER 135-559

46.13 RESPONSIBLE ENGINEER D. Horelick


 
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