Option Multiple Replay | Output modes |
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Option Multiple Replay
The option Multiple Replay allows the generation of data blocks with multiple trigger events without restarting the hardware. The
Output modes
Standard Mode
With every detected trigger event one data block is replayed. The length of one Multiple Replay segment is set by the value of the posttrigger register. The total amount of samples to be replayed is defined by the memsize register.
In most cases memsize will be set to a a multiple of the segment size (postcounter). The table below shows the register for enabling Multiple Replay. For detailed information on how to setup and start the standard replay mode please refer to the according chapter earlier in this manual.
Multiple Replay is not compatible with continuous output.
Register | Value | Direction | Description |
SPC_MULTI | 220000 | r/w | Enables Multiple Replay mode. |
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SPC_MEMSIZE | 10000 | r/w | Defines the total amount of samples to be replayed. |
SPC_POSTTRIGGER | 10100 | r/w | Defines the size of one Multiple Replay segment. |
FIFO Mode
The Multiple Replay in FIFO Mode is similar to the Multiple Replay in Standard Mode. The segment size is also set by the postcounter register.
In contrast to the Standard mode you cannot programm a certain total amount of samples to be replayed. The gene- ration is running until the user stops it. The data is transfered FIFO block by FIFO block by the driver to the board. These blocks can be online generated by the user program. This mode significantly reduces the average data transfer rate
on the PCI bus. This enables you to use faster sample rates then you would be able to in FIFO mode without Multiple Replay.Usually the FIFO blocks are multiples of the Multiple Replay segments.
The advantage of Multiple Replay in FIFO mode is that you can stream data online from the host system to the board, so you can replay a huge amount of data from the hard disk. The table below shows the dedicated register for enabling Multiple Replay. For detailed information how to setup and start the board in FIFO mode please refer to the according chapter earlier in this manual.
Register | Value | Direction | Description |
SPC_MULTI | 220000 | r/w | Enables Multiple Replay mode. |
SPC_POSTTRIGGER | 10100 | r/w | Defines the size of one Multiple Replay segment. |
Trigger modes
In Multiple Replay mode all of the board’s trigger modes are available except the software and pattern trigger. De- pending on the different trigger modes, the chosen sample rate, used channels and activated board synchronization, (see relevant chapter for details about synchronizing multi- ple boards) there are different delay times between the trig- ger event and the first replayed data (see figure).
This internal delay is necessary as the board is equipped with dynamic RAM, which needs refresh cycles to keep the data in memory when the board is not replaying.
The delay is fixed for a certain board setup. All possible delays in samples between the trigger event and the first re- played sample are listed in the table below.
The patterntrigger modes of digital I/O boards cannot be used with multiple replay.
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