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51.1 GENERAL DESCRIPTION . . . . . . . . . . . . . . 51-1

51.2 APPLICATION . . . . . . . . . . . . . . . . . . 51-1

51.3 SOLID STATE SWITCHES . . . . . . . . . . . . . . 51-1

51.4 CAMAC CONTROL . . . . . . . . . . . . . . . . . 51-2

51.5 CONSTRUCTON . . . . . . . . . . . . . . . . . . 51-3

51.5.1 Single Width CAMAC Module . . . . . . . . . . 51-3

51.5.2 Front Panel with following items: . . . . . . 51-3

51.6 DRAWING PACKAGE NUMBER . . . . . . . . . . . . . 51-3

51.7 RESPONSIBLE ENGINEERS . . . . . . . . . . . . . 51-3 CHAPTER 51 BEAM POSITION MULTIPLEXER (SP10T)

51.1 GENERAL DESCRIPTION The Single Pole 10 Throw modules (SP10T) were designed to multiplex up to ten Beam Position Monitors (BPM) to a single BPM signal processor. The solid state switch is made using PIN diodes. The switch position is controlled by a CAMAC write function, all contacts can be opened with a CLEAR command, and the switch position can be read back via CAMAC.

51.2 APPLICATION Typically one electrode of each BPM is connected to an SP10T input, the remaining three electrodes are similarly connected to the inputs of three other SP10T's. The output of each SP10T feeds the corresponding input of a BPM ADC. When all contacts are open the BPM ADC is not connected to any BPM. By closing a set of contacts on all four SP10T's one BPM is connected to the ADC.

51.3 SOLID STATE SWITCHES PIN diodes can switch short, bipolar impulses as large as +/-15 volts, with a control current of 50 to 100 milliamp only. When the diode does not conduct, it exhibits a capacitance of 0.3 pico-farad and when it conducts it's forward impedence amount to only a few ohms. The reproducibility should be at least 0.5%, therefore there is no need to sort the diodes. Switching from one station to another takes the order of a few microseconds. The switches are open when the control current is zero. ______________________________ For further details on the SP10T, see SINGLE PASS COLLIDER MEMO CN-126 and CN-185.


BEAM POSITION MULTIPLEXER (SP10T) Page 51-2

51.4 CAMAC CONTROL o Q and X Q and X are returned true for all valid functions. o F23 A0-15 -- CLEAR All contacts are opened. The latches holding the data do not require a CLEAR between WRITE commands since they can be overwritten. o F22 A0-15 -- WRITE The 10 write lines control the 10 inputs of the SP10T's as shown below. They are latched with S1. +-------+--------+----------+---------------+ |SP10T | Bus | Binary | Hexadecimal | |input | line | word | value | +-------+--------+----------+---------------+ | 1 | W1 |0000000001| 1 | | 2 | W2 |0000000010| 2 | | 3 | W3 |0000000100| 4 | | 4 | W4 |0000001000| 8 | | 5 | W5 |0000010000| 10 | | 6 | W6 |0000100000| 20 | | 7 | W7 |0001000000| 40 | | 8 | W8 |0010000000| 80 | | 9 | W9 |0100000000| 100 | | 10 | W10 |1000000000| 200 | +-------+--------+----------+---------------+ o F2 A0-15 -- READ This function tests the latched command on the transistors which close or open the PIN diode switches. The format is the same as for WRITE.


BEAM POSITION MULTIPLEXER (SP10T) Page 51-3

51.5 CONSTRUCTON

51.5.1 Single Width CAMAC Module

51.5.2 Front Panel with following items: o 10 SMA sockets for signals from BPMs. o 1 SMA connector for output to BPM CAMAC module o 2 LEDs indicating "N" and "X"

51.6 DRAWING PACKAGE NUMBER 447-012

51.7 RESPONSIBLE ENGINEERS J-C. Denard, G. J. Oxoby, J-L. Pellegrin, and V. Smith


 
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Contact (until Aug. 15, 1996): Jeffrey Miller
Owner: Bob Sass

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