User manual

2.3.36 AcqrsD1_configChannelCombination
Purpose
Configures how many converters are to be used for which channels. This routine is for use with some
DC271-FAMILY instruments, the 10-bit-FAMILY, the AC/SC240, and the AP240/AP235 Signal Analyzer
platforms.
Parameters
Input
Name Type Description
instrumentID ViSession Instrument identifier
nbrConvertersPer
Channel
ViInt32 = 1 all channels use 1 converter each (default)
= 2 half of the channels use 2 converters each
= 4 1/4 of the channels use 4 converters each
usedChannels ViInt32 bit-field indicating which channels are used. See
discussion below
Return Value
Name Type Description
status ViStatus Refer to Table 2-1 for error codes.
Discussion
The acceptable values for 'usedChannels' depend on 'nbrConvertersPerChannel' and on the number of
available channels in the digitizer:
A) If 'nbrConvertersPerChannel' = 1, 'usedChannels' must reflect the fact that ALL channels are available
for use. It accepts a single value for a given digitizer:
'usedChannels' = 0x00000001 if the digitizer has 1 channel
= 0x00000003 if the digitizer has 2 channels
= 0x0000000f if the digitizer has 4 channels
B) If 'nbrConvertersPerChannel' = 2, 'usedChannels' must reflect the fact that only half of the channels may
be used:
'usedChannels' = 0x00000001 use channel 1 on a 2-channel digitizer
= 0x00000002 use channel 2 on a 2-channel digitizer
= 0x00000003 use channels 1+2 on a 4-channel digitizer
= 0x00000005 use channels 1+3 on a 4-channel digitizer
= 0x00000009 use channels 1+4 on a 4-channel digitizer
= 0x00000006 use channels 2+3 on a 4-channel digitizer
= 0x0000000a use channels 2+4 on a 4-channel digitizer
= 0x0000000c use channels 3+4 on a 4-channel digitizer
C) If 'nbrConvertersPerChannel' = 4, 'usedChannels' must reflect the fact that only 1 of the channels may be
used:
'usedChannels' = 0x00000001 use channel 1 on a 4-channel digitizer
= 0x00000002 use channel 2 on a 4-channel digitizer
= 0x00000004 use channel 3 on a 4-channel digitizer
= 0x00000008 use channel 4 on a 4-channel digitizer
NOTE: Digitizers which don't support channel combination, always use the default
'nbrConvertersPerChannel' = 1, and the single possible value of 'usedChannels'
NOTE: Changing the channel combination doesn't change the names of the channels; they are always the
same.
NOTE: If digitizers are combined with AS bus, the channel combination applies equally to
all participating digitizers.
Programmer’s Reference Manual Page 70 of 210