sis3300

In start mode an external start input is required to start digitization. Digitization stops either when the desired number of samples have been acquired or when an external stop input is provided.

The start input is the second from the top (input 3). The stop input is the third from the top (input 2).

In stop mode, the digitizer is continuously digitizing. Digitization then stops when an NIM pulse is presented to input 2 (third from the top).

Note that in stop mode, the actual acquired data my not be at the beginning of the digitizer data. See OUPUT DATA FORMAT below for more information.

In gate mode, a gate signal is presented to the start input (input 3 second from the top). digitization begins on the falling edge of the gate and ends on the rising edge of the gate, or when the maximum number of samples has been acquired (if the gate is wider than the time required to digitize the maximum number of samples).

Sets the VME base address of the module. For the 3300, this is set via jumpers that control the top four bits of VME address. For the 3301, this is set via a pair of rotary switches that allow the top eight bits of the VME address to be set.

Sets the digitizer clock source. This can be one of several internal clock frequencies available or one the external clock modes. The default clock source is 100Mhz The valid clock sources are:

Selects the mode of the digitizer. Defaults to start mode. See DESCRIPTION above for a summary of the modes. Note that start and stop modes represent special use cases of the digitizers's start/stop trigger mode while gate is the digitizer's gate trigger mode.

The -mode selected can affect the way you need to decode the data from each event. See OUTPUT DATA FORMAT below for more information.

If the value of this option is disabled, the start delay is not enabled. Otherwise, the value must be a positive integer in the range [0,65535] and is the number of clock ticks the digitizer start is delayed before actually being applied.

This option defaults to disabled.

Same as -startdelay above, however the delay, if enabled, applies to the stop time.

Defaults to disabled

Selects the maximum number of sample that will be acquired. This defaults to 128K. The following values are allowed: 128K, 16K, 4K, 2K, 1K, 512, 256, 128. Note that the K multiplier in the list above means 1024.

It is possible that fewer than -samples will be acquired. This can happen in:

• In start mode if there is a stop input that fires to the time required to digitize all samples.

• In stop mode if the stop comes soon enough after the digitizer is started by the VMUSB that not all the samples have been digitized.

• In gate mode if the gate is narrower than the time required to digitize all samples.

The data structure allows you to determine if this is the case. See OUTPUT DATA FORMAT for information about this.

This option defaults to 128K

A list of 8 booleans, one per digitizer channel. If a list element is true, the channel threshold is applied for a crossing from above to below the threshold. If false, the channel threshold is applied to a crossing from below the threshold to above it.

See -thresholds below for more information. Defaults to an 8 element list of false

A list of 8 integer in the range [0,4096) for the SIS 3300 and [0,16384) for the SIS3301. If the input signal crosses this value in the direction specified by the corresponding -thresholdslt value, a pulse is sent on the trigger output (bottom lemo).

This pulse can be cabled to the start or stop input to directly trigger the digitizer or sent to external trigger logic as a term in a more complex trigger scheme.

The default value is a list of 8 16383 values.

This parameter is a list of four integers, one per channel group that specifies the minimum number of clock ticks the trace in a group must be below the threshold to result in a trigger when a channel's thresholdslt value is true. This defaults to a list of 40 which disables the use of this parameter. The value must be in the range [0, 16). A value of 0 disables the enforcement of this parameter.

Defaults to a list of four 0 values

Same as -minletime except that this specifies the number of consecutive clock ticks a channel must be above the threshold value when -thresholdslt for the channels is false..

As with -minletime, this defaults to a list of four 0 values.

List of four integers in the range [0,16), one for each group of two channels. If the value for a group is 0 (the default), the settable output gate width feature is disabled. Otherwise, this value represents the desired output width of the trigger in clock ticks.

a list of four 0 values

List of four booleans (defaults to all true), one for each ADC channel group. If a group's flag is true it is read out, if not it is not read out.

Defaults to a group of four false valsuss.

This 16 bit value is inserted into the data from the module prior to the data from each group. See OUTPUT DATA FORMAT below for more information about where this appears.

This defaults to 0xfadc

This 16 bit value is inserted into the data from the module after the data from each group. See OUTPUT DATA FORMAT below for more information. Defaults to 0xffff

Is the value of the -header option. If not configured by you this defaults to 0xfadc

Is the value of the -trailer option

See section 4.25 of the SIS3300/3301 manual for the detailed format of these 32 bits.

The bottom 17 bits of this value modula the number of samples you have selected are sample in the data from the group after which the data have ended. In the start and gate mode the trace always begins at the first data item and this value indicates the sample after which data end. In start mode, and gate mode, this may indicate fewer samples have been digitized than were acquired if, for example there is an external stop in start mode or, in gate mode, if the gate is short relative to the selected sample size.

In stop mode, the digitizer treats the data buffer as a circular buffer into which it is continously digitizing the input. The stop signal then indicates when digitization ends ( the actual stop may be delayed by the -stopdelay). Therefore in stop mode the bottom 17 bits modula the -samples together with bit 19 (the wrap bit) indicate at which sample the trace starts.

If the wrap bit is not set, then trace begins at the first sample in the buffer and ends at the sample just prior to the value in the bottom 17 bits. If the wrap bit is set, data begins at the sample number in the data indicated by the bottom 17 bits and wraps circulalry to the beginnning of the data before ending in the sample just prior to the first sample.

If you are using the internal thresholds, bits 24-31 indicate which, if any, channels satisfied their threshold conditions. Bit 31 represents the state of the channel 1 trigger and bit 24 the state of the channel 8 trigger.

This is the actual number of samples that will appear in the data buffer. At present, (this may change), in start and in stop mode, this is the number of samples selected by -samples. In gate mode, this value repeats the trigger event directory and the bottom 17 bits indicate the number of samples acquired.

This is the raw sample data, 32 bits per sample containing a sample from each ADC in the group of two samples as shown in section 4.33 of the SIS3300/3301 manual. Note that to decode the data you will need to know if the digitizer is an SIS3300 (12 bits of data over range flag in bit 12) or an SIS3301 (14 bits of data over range flag in bit 14).

These 16 bits are the value of the -trailer option. If not configured by you, this defaults to 0xffff. Note that since bit 15 is set, this is not a legal conversion value from the AD and therefore is distinguishable from real data. I recommend that if you choose a different -trailer from the default value, that you select one that has the top bit set.