The VME Multiscaler SIS3820

The easiest way is to operate the module as a scaler counter which will be sufficient for most of the $\mathrm{\mu SR}$ applications at PSI.

To setup with two user bits on either input 2 or 3 of the front panel Lemo connectors choose 24-bit scaler data format; the upper 8 bit are then used for channel number and user bit. Without user bit information the scaler are read with the full 32-bit range.

sis3820_key_reset(device, sis3820_base);
control = SIS3820_CONTROL_INPUT_MODE3 + SIS3820_SCALER_DATA_FORMAT_24BIT;
sis3820_operation_mode_write(device, sis3820_base, control);

/* start counting */
sis3820_key_enable(device, sis3820_base);
...
/* read periodically */
sis3820_scaler_read(device, sis3820_base, A32BLT32, 32, blt_data);
...
/* at end of acquisition, disable device */
sis3820_key_disable(device, sis3820_base);