Home Scalers

SIS3820 multi purpose scaler


Multiscaler (MCS)
Latching Scaler
Preset Scaler
Histogramming Scaler


The SIS3820 is the next step in Struck Innovatives continueing effort to develop state of the art scaler/counter boards and associated firmware for a variety of applications. It combines the functionality of standard counters and multiscalers without compromising performance. The use of standard commodity market memory solutions in combination with recent FPGA technology results in unprecedented functionality.

The SIS3820 scaler is a single width 6U VME card, no non standard voltages are required. The unit comes with a 20 pin header connector for the control section and two 34 pin headers for the counters (ECL and flat cable TTL version) or via 8 LEMO connectors for the control section and 32 LEMOs for the counter section (NIM and LEMO TTL version). RS422/RS485 is available as input option. The front panel design is compatible with the SIS380x. 32 additional inputs can be fed to the scaler via VME64x transition cards. The SIS3820 accepts inputs with a frequency of up to 250 MHz (50 MHz on the P2 fed inputs).




32 channels (+32 channel option via P2 Minimum dwell time 220ns (for 8 channels)
24/32-bit channel depth External/VME time slice advance
250 MHz (ECL inputs)/50 MHz on rear inputs Synchronous clock shadow register
ECL/TTL/LVDS or NIM inputs Read on the fly accuracy to lowest bit
Flat cable/LEMO mixed input configurations Field upgradeable firmware
64 MByte default (512 MByte optional) memory size VME64x side shielding
FIFO memory emulation mode A16/A24/A32 D16/D32/BLT32/MBLT64/2eVME/CBLT
VME access/user LED VME interrupt capabilities
2 front panel user bits (in 24-bit mode) VME64x connectors
copy in progress output Broadcast features
2 x preset for arbitrary channel of 16ch group Single +5 V supply


VME readout speed:

Following block transfer speeds were measured with a SIS1100/3100 on a standard (i.e. non VME64x) VME backplane from the SIS3820s SDRAM.

Transfer type Speed
BLT32 25 MBytes/s
MBLT64 50 MBytes/s
2e VME 88 MBytes/s


Block Diagram