These options are available to purchase and enhance the functionality of the M3i.32xx and 41xx series boards. The most popular option called Multiple-Recording can be purchased on its own or combined with other useful ones listed below in cost effective options packs. Please contact Dataquest Solutions for pricing information on these enhancements.
| ABA mode | Synchronisation by star hub | Multiple recording | BaseXIO | Time stamp |
ABA mode this allows changing from long-term slow and continuous data logging (through a process of sample decimation), to ultra-fast acquisition on a trigger event. This is handled by the hardware. This is more efficient than having to write code in a post-process program and helps isolate in detail interesting events from reams of data.
In the above diagram the decimated data capture points are shown as blue lines. When a trigger is applied the data is recorded at the full clock speed, here depicted by the green lines in section B. Data is captured for a user definable numbers of times. Pre and post trigger data can be recorded at the full rate if required so that analysis of the signal leading up to the trigger, as well as that following can be performed.
ABA mode significantly reduces stored file sizes. At the sort of rates these ultra high-speed cards can operate, this is a big advantage. The level of decimation can be set in the driver code or the SBench software. The trigger point can be external an TTL pulse, or from the amplitude of the analogue input signal.
The Star Hub is an additional module for all M3i boards to allow synchronisation without any phase delay between cards, hence all channels are perfectly synchronised too and comes in two forms:
The SH4 option requires no addtional slot, the SH8 has a higher daughterboard fitted to master M3i so does required the space occupied by an adjacent slot, however it allows a up to 16 analogue channels (8 M3i cards each with 2 channels) to be connected.
Across the star hub, clock and trigger
information is common and exchanged between all the boards.
Any board may be
assigned the master trigger - then used to initiate recording across all boards.
Star-Hub Synchronisation requires only one purchase per system of boards.
Multiple Recording allows the capture of signal data associated with each of several trigger events, without having to restart the hardware. Trigger events which repeat at a very high rate could thus be recognised with this option without risk of any being missed. A trigger re-arm period is required immediately after each capture event, however for the M3i series of boards this is less than 32 samples in length. Should you intentionally wish for an extended delay between trigger arrival and each recording this is software programmable up to 32 Giga samples!
The memory of the board will be divided into several segments of the same size. Each segment will be filled with data when a trigger event occurs.
Multiple Recording may be combined with the Time stamp option to record the start time of a segment.
BaseXIO (Asynchronous I/O and triggers).
This option provides digital input and output lines asynchronous to the analogue inputs of the A/D cards. One of their advantages is their 32mA source capability, so with this simple-to-use versatile enhancement it is possible to control a wide range of external instruments or other equipment, such as that producing a signal source. Eight asynchronous digital I/O are available and can be programmed 8 inputs, 8 outputs or split 4/4. When using the BaseXIO lines as digital I/O, they are completely independent from the board’s function, data direction or sampling rate and directly controlled by software. Special purpose lines are also added to provide two secondary TTL trigger lines to allow an AND type operation within the main external trigger starting the board. So for example you can start and stop the board by monitoring a condition at two sources. Finally a RefClock input comes with this option to allow the Time Stamp option (see below) to accept a precise 1Hz pulse from an external timer card.
 | The time stamp function allows recording of trigger moments relative to the start of recording or synchronised to an external radio clock. The time stamp function is designed as an enhancement to the Multiple Recording and the Gated Sampling mode but could also be used without any of these options. The memory of the time stamp function is a FIFO buffer and this allows continuous signal recording with time stamps. Each time stamp is defined by samples and therefore the rate of the A/D converter clock. The relationship between trigger events and the count are set by the modes as described below. |
Standard Mode
In standard mode the time stamp counter is set to zero once, with a call to TS_RESET. After this call the counter counts continuously. The time stamp of all recorded trigger events are referenced on this common zero time. With this mode the exact time difference between different recordings may be calculated.
StartReset Mode
When card is started ready for a trigger it will not to start to record data until a trigger is received. In multiple record mode many such trigger events may be very close together to capture many such individual recordings and when each such recording segment is finished the board is automatically re-started ready for the next trigger. In the StartReset mode a time stamp value is given calculated from the counter which starts from zero after each current restart. In addition, if this is used instead with gated sampling, a time stamp will show the start and also the end of the gate.
RefClock Mode
The counter is divided into a HIGH and a LOW part. The HIGH part counts the seconds that have elapse since reset of the whole counter and references the seconds signal of an external radio clock, or any user precise 1Hz signal. The LOW part is reset every second, and defines the position of the trigger event within the current second. The timing signal must be fed into the time stamp module as a TTL signal. This mode allows the absolute time of a trigger event to be recorded. Alternatively, the HIGH counter part could also be used to count the number of external triggers
Click for more information plus diagrams on Time stamp: [Time stamp presentation PDF link (940Kbyte)]
The most popular option above called Multiple-Recording can be purchased on its own
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© Dataquest Solutions 14.07.09.
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