Spectrum M3i.4830, Руководство по оборудованию

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ABA mode (dual timebase) General information
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The total number of samples to be recorded to the on-board memory in standard mode is defined by the SPC_MEMSIZE register.
FIFO Mode
The ABA FIFO Mode is similar to the Multiple Recording FIFO mode. In contrast to the standard mode it is not necessary to program the
number of samples to be recorded. The acquisition is running until the user stops it. The data is read block by block by the driver as described
under Single FIFO mode example earlier in this manual. These blocks are online available for further data processing 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 ABA.
The number of segments to be recorded must be set separately with the register shown in the following table:
Limits of pre trigger, post trigger, memory size
The maximum memory size parameter is only limited by the number of activated channels and by the amount of installed memory. Please
keep in mind that each samples needs 2 bytes of memory to be stored. Minimum memory size as well as minimum and maximum post trigger
limits are independent of the activated channels or the installed memory.
Due to the internal organization of the card memory there is a certain stepsize when setting these values that has to be taken into account.
The following table gives you an overview of all limits concerning pre trigger, post trigger, memory size, segment size and loops. The table
shows all values in relation to the installed memory size in samples. If more memory is installed the maximum memory size figures will increase
according to the complete installed memory
All figures listed here are given in samples. An entry of [32G - 8] means [32 GSamples - 8 ] = 34,359,738,360 samples.
The given memory and memory / divider figures depend on the installed on-board memory as listed below:
Please keep in mind that this table shows all values at once. Only the absolute maximum and minimum values are shown. There might be
additional limitations. Which of these values is programmed depends on the used mode. Please read the detailed documentation of the mode.
SPC_REC_STD_ABA 8h Data acquisition to on-board memory for multiple trigger events. While the multiple trigger events are stored with pro-
grammed sampling rate the inputs are sampled continuously with a slower sampling speed.
Register Value Direction Description
SPC_MEMSIZE 10000 read/write Defines the total number of samples to be recorded.
Register Value Direction Description
SPC_CARDMODE 9500 read/write Defines the used operating mode
SPC_REC_FIFO_ABA 80h Continuous data acquisition for multiple trigger events together with continuous data acquisition with a slower sam-
pling clock.
Register Value Direction Description
SPC_LOOPS 10020 read/write Defines the number of segments to be recorded
0 Recording will be infinite until the user stops it.
1 … [4G - 1] Defines the total segments to be recorded.
Activated Used Memory size Pre trigger Post trigger Segment size Loops
Channels Mode SPC_MEMSIZE SPC_PRETRIGGER SPC_POSTTRIGGER SPC_SEGMENTSIZE SPC_LOOPS
Min Max Step Min Max Step Min Max Step Min Max Step Min Max Step
1 channel Standard Single 16 Mem 8 defined by post trigger 8 8G - 8 8 not used not used
Standard Multi/ABA 16 Mem 8 8 8k 8 8 Mem/2 8 16 Mem/2 8 not used
FIFO Single not used 8 8k 8 not used 16 8G - 8 8 0 (
∞
) 4G - 1 1
FIFO Multi/ABA not used 8 8k 8 8 8G - 8 8 16 pre+post 8 0 (
∞
) 4G - 1 1
2 channels Standard Single 16 Mem/2 8 defined by post trigger 8 8G - 8 8 not used not used
Standard Multi/ABA 16 Mem/2 8 8 4k 8 8 Mem/4 8 16 Mem/4 8 not used
FIFO Single not used 8 4k 8 not used 16 8G - 8 8 0 (
∞
) 4G - 1 1
FIFO Multi/ABA not used 8 4k 8 8 8G - 8 8 16 pre+post 8 0 (
∞
) 4G - 1 1
Installed Memory
128 MSample 256 MSample 512 MSample 1 GSample 2 GSample
Mem 128 MSample 256 MSample 512 MSample 1 GSample 2 GSample
Mem / 2 64 MSample 128 MSample 256 MSample 512 MSample 1 GSample
Mem / 4 32 MSample 64 MSample 128 MSample 256 MSample 512 MSample