Fifo Mode; Limits Of Pre Trigger, Post Trigger, Memory Size - Spectrum M2p.59 Series Hardware Manual

Limits of pre trigger, post trigger, memory size

Memsize must be set to a a multiple of the segment size. The table below shows the register for enabling standard ABA mode. For detailed
information on how to setup and start the standard acquisition mode please refer to the according chapter earlier in this manual.
Register
SPC_CARDMODE
SPC_REC_STD_ABA
The total number of samples to be recorded to the on-board memory in standard mode is defined by the SPC_MEMSIZE register.
Register
SPC_MEMSIZE

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.
Register
SPC_CARDMODE
SPC_REC_FIFO_ABA
The number of segments to be recorded must be set separately with the register shown in the following table:
Register
SPC_LOOPS
0
1 ... [4G - 1]
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
Table 86: Overview of all limits of pre-trigger, post-trigger and memory size for the different channel activations and acquisition modes
Activated Used
Channels Mode
1 Ch Standard Single
Standard
Multi/ABA
Standard Gate
FIFO Single
FIFO Multi/ABA
FIFO Gate
2 Ch Standard Single
Standard
Multi/ABA
Standard Gate
FIFO Single
FIFO Multi/ABA
150
Value Direction
9500 read/write
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.
Value Direction
10000 read/write
Value Direction
9500 read/write
80h Continuous data acquisition for multiple trigger events together with continuous data acquisition with a slower sam-
pling clock.
Value Direction
10020 read/write
Recording will be infinite until the user stops it.
Defines the total segments to be recorded.
Memory size Pre trigger
SPC_MEMSIZE SPC_PRETRIGGER
Min Max Step Min
16 Mem 8 8 Mem - 8
(defined by mem and post)
16 Mem 8 8
(defined by segment and
16 Mem 8 8
not used 8
not used 8
(defined by segment and
not used 8
16 Mem/2 8 8 Mem/2 - 8
(defined by mem and post)
16 Mem/2 8 8
(defined by segment and
16 Mem/2 8 8
not used 8
not used 8
(defined by segment and
(c) Spectrum Instrumentation GmbH
Description
Defines the used operating mode
Description
Defines the total number of samples to be recorded.
Description
Defines the used operating mode
Description
Defines the number of segments to be recorded
Post trigger
SPC_POSTTRIGGER
Max Step Min Max
8 8 8G - 8
32k 8 8 Mem - 8
(Limited by max pretrigger)
post)
32k 8 8 Mem - 8
32k 8 not used
32k 8 8 8G - 8
(Limited by max pretrigger)
post)
32k 8 8 8G - 8
8 8 8G - 8
16k 8 8 Mem/2 - 8
(Limited by max pretrigger)
post)
16k 8 8 Mem/2 - 8
16k 8 not used
16k 8 8 8G - 8
(Limited by max pretrigger)
post)
ABA mode (dual timebase)
Segment size
SPC_SEGMENTSIZE
Step Min Max Step Min
8 not used
8 16 Mem 8
8 not used
16 8G - 16 8 0 ()
8 16 pre+post 8 0 ()
8 not used 0 ()
8 not used
8 16 Mem/2 8
8 not used
16 8G - 16 8 0 ()
8 16 pre+post 8 0 ()
Loops
SPC_LOOPS
Max Step
not used
not used
not used
4G - 1 1
4G - 1 1
4G - 1 1
not used
not used
not used
4G - 1 1
4G - 1 1