Rasnik minimastermux

The MiniMasterMux is a prototype of the combination of MasterMux and USA15Mux. The MMX box measures 19 * 19 * 6 cm. It requires a single power supply of 24V, 1A. Four large connectors for the RasMux go to D25 connectors on the lid. next to them the grabber connection. Several empty positions where the LPT interface could be mounted in case the RS232 interface could not be realized in time. The mezzanine card contains this RS232 interface using an AVR microprocessor. One connector on this board is for the D9 connection with the PC. The other one is used to load the microprocessor's code, which is stored in flash memory.

The MiniMasterMux is a combination of MasterMux and USA15Mux. The MasterMux will have 16 channels, the MiniMasterMux handles 4 RasMuxes (version 2 RasMux only). The MMX directly connects to the framegrabber and is controlled via the PC's serial port. It switches the power to the RasMuxes, thus reducing power dissipation on the chambers further (RasMux_V2 dissipates far less than V1).
The MasterMux will not contain the microprocessor but talks with the USA15 Mux, using the Very Simple Protocol. This VSP uses 4 (differential) lines similar to the way JTAG operates. The same protocol is used between the MasterMux and the RasMux. A simple vertical addressing scheme is used to address either the USA15Mux, MasterMux or RasMux. The horizontal steering in the tree of multiplexers is contained in the data. The USA15Mux is constantly powered and handles six MasterMuxes. Of all MasterMuxes and RasMuxes, connected to one USA15Mux, maximum two RasMuxes and one MasterMux are powered. In this way the total power dissipated in the experimental hall is less than 30 W, including RasLeds and RasCams.

You can go to

• the RASNIK for ATLAS main page.
• the NIKHEF electronics for ATLAS overview page.
• the NIKHEF home page.

updated: may 2002