Spectrum M2p.59 Series, Hardware Manual, Page: 91 / 190

Acquisition modes Data organization
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Data organization
Data is organized in a multiplexed way in the transfer buffer. If using 2 channels data of first activated channel comes first, then data of
second channel.
The samples are re-named for better readability. A0 is sample 0 of channel 0, B4 is sample 4 of channel 1, and so on.
Sample format
If the card is using 16 bit A/D samples, the are stored in twos complement in the 16 bit data word. 16 bit resolution means that data is
ranging from -32768…to…+32767.
Up to three digital inputs (provided via the Multi Pupose I/O lines X1, X2 and X3) can be acquired synchronously and stored within the data
samples of any active channel. This will reduce the available resolution of these channel(s) to either 15 bit, 14 bit or 13 bit, depending on
the number of incorporated digital lines. For a detailed description on how to enable additional synchronous digital inputs, please see the
„“Multi Purpose I/O Lines“ section later in this manual.
Any channels that will not store any digital inputs within their samples still provide the full 16 bit resolution. :
* Any X-input can be used as a source for that digital channel, except X0, which is output only.
Table 42: Spectrum API: overview of data organization in memory for different channel configurations
Activated
Channels
Ch
0
Ch
1
Ch
2
Ch
3
Ch
4
Ch
5
Ch
6
Ch
7
Samples ordering in buffer memory starting with data offset zero
1 channel X A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 ...
Any allowed active channel, as mentioned in the „Channel Selection“ section, will lead to a data stream over time.
1 channel
X G0 G1 G2 G3 G4 G5 G6 G7 G8 G9 G1
0
G1
1
G1
2
...
2 channels X X A0 B0 A1 B1 A2 B2 A3 B3 A4 B4 A5 B5 A6 ...
Any allowed combination of two channels, as mentioned in the „Channel Selection“ section, will lead multiplexed data stream over time with a linear channel ordering. For each sam -
ple point in time the samples are multiplexed with the ascending channel number.
2 channels
X X C0 D0 C1 D1 C2 D2 C3 D3 C4 D4 C5 D5 C6 ...
4 channels X X X X A0 B0 C0 D0 A1 B1 C1 D1 A2 B2 C2 D2 A3 ...
Any allowed combination of two channels, as mentioned in the „Channel Selection“ section, will lead multiplexed data stream over time with a linear channel ordering. For each sam -
ple point in time the samples are multiplexed with the ascending channel number.
4 channels
X X X X A0 C0 D0 H0 A1 C1 D1 H1 A2 C2 D2 H2 A3 ...
8 channels X X X X X X X X A0 B0 C0 D0 E0 F0 G0 H0 A1 B1 C1 D1 E1 F1
Table 43: Spectrum API: data organization for different digital input option configurations
Standard Mode 1 digital input enabled 2 digital inputs enabled 3 digital inputs enabled
Data bit 16 bit
ADC resolution
15 bit
ADC resolution
14 bit
ADC resolution
13 bit
ADC resolution
D15 ADx Bit 15 (MSB) Digital bit 0 (any X input)* Digital bit 0 (any X input)* Digital bit 0 (any X input)*
D14 ADx Bit 14 ADx Bit 15 (MSB) Digital bit 1 (any X input)* Digital bit 1 (any X input)*
D13 ADx Bit 13 ADx Bit 14 ADx Bit 15 (MSB) Digital bit 2 (any X input)*
D12 ADx Bit 12 ADx Bit 13 ADx Bit 14 ADx Bit 15 (MSB)
D11 ADx Bit 11 ADx Bit 12 ADx Bit 13 ADx Bit 14
D10 ADx Bit 10 ADx Bit 11 ADx Bit 12 ADx Bit 13
D9 ADx Bit 9 ADx Bit 10 ADx Bit 11 ADx Bit 12
D8 ADx Bit 8 ADx Bit 9 ADx Bit 10 ADx Bit 11
D7 ADx Bit 7 ADx Bit 8 ADx Bit 9 ADx Bit 10
D6 ADx Bit 6 ADx Bit 7 ADx Bit 8 ADx Bit 9
D5 ADx Bit 5 ADx Bit 6 ADx Bit 7 ADx Bit 8
D4 ADx Bit 4 ADx Bit 5 ADx Bit 6 ADx Bit 7
D3 ADx Bit 3 ADx Bit 4 ADx Bit 5 ADx Bit 6
D2 ADx Bit 2 ADx Bit 3 ADx Bit 4 ADx Bit 5
D1 ADx Bit 1 ADx Bit 2 ADx Bit 3 ADx Bit 4
D0 ADx Bit 0 (LSB) ADx Bit 1 (LSB) ADx Bit 2 (LSB) ADx Bit 3 (LSB)