Acquisition modes
Overview
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Acquisition modes
Your card is able to run in different modes. Depending on the selected mode there are different registers that each define an aspect of this
mode. The single modes are explained in this chapter. Any further modes that are only available if an option is installed on the card is doc-
umented in a later chapter.
Overview
This chapter gives you a general overview on the related registers for the different modes. The use of these registers throughout the different
modes is described in the following chapters.
Setup of the mode
The mode register is organized as a bitmap. Each mode corresponds to one bit of this bitmap. When defining the mode to use, please be
sure just to set one of the bits. All other settings will return an error code.
The main difference between all standard and all FIFO modes is that the standard modes are limited to on-board memory and therefore can
run with full sampling rate. The FIFO modes are designed to transfer data continuously over the bus to PC memory or to hard disk and can
therefore run much longer. The FIFO modes are limited by the maximum bus transfer speed the PC can use. The FIFO mode uses the complete
installed on-board memory as a FIFO buffer.
However as you’ll see throughout the detailed documentation of the modes the standard and the FIFO mode are similar in programming and
behavior and there are only a very few differences between them.
Acquisition modes
Register
Value
Direction
Description
SPC_CARDMODE
9500
read/write
Defines the used operating mode, a read command will return the currently used mode.
SPC_AVAILCARDMODES
9501
read
Returns a bitmap with all available modes on your card. The modes are listed below.
Mode
Value
Description
SPC_REC_STD_SINGLE
1h
Data acquisition to on-board memory for one single trigger event.
SPC_REC_STD_MULTI
2h
Data acquisition to on-board memory for multiple trigger events. Each recorded segment has the same size. This mode is described in greater
detail in a special chapter about the Multiple Recording option.
SPC_REC_STD_GATE
4h
Data acquisition to on-board memory using an external Gate signal. Acquisition is only done as long as the gate signal has a programmed
level. The mode is described in greater detail in a special chapter about the Gated Sampling option.
SPC_REC_STD_ABA
8h
Data acquisition to on-board memory for multiple trigger events. While the multiple trigger events are stored with programmed sampling rate
the inputs are sampled continuously with a slower sampling speed. The mode is described in a special chapter about ABA mode option.
SPC_REC_FIFO_SINGLE
10h
Continuous data acquisition for one single trigger event. The on-board memory is used completely as FIFO buffer.
SPC_REC_FIFO_MULTI
20h
Continuous data acquisition for multiple trigger events.
SPC_REC_FIFO_GATE
40h
Continuous data acquisition using an external gate signal.
SPC_REC_FIFO_ABA
80h
Continuous data acquisition for multiple trigger events together with continuous data acquisition with a slower sampling clock.
