VXI VT1422A - Manual (Page 325)

VT1422A Command Reference 323 Chapter 7
ROUTe
ROUTe
The ROUTe subsystem provides a method to define the sequence of channels in the
VT1422A’s Analog Input scan list. Note that any analog input channels specified in
an algorithm definition also affect the contents of this scan list. Queries are provided
to determine the overall channel list definition including analog output channels as
well as digital input and output channels.
Subsystem Syntax ROUTe
:SEQuence
:DEFine (@<ch_list>)
:DEFine?
:POINts?
ROUTe:SEQuence:DEFine
ROUTe:SEQuence:DEFine (@<ch_list>) adds channels to the analog input scan
list. (All digital and analog output channels must be specified in the algorithm.)
Channels specified with ROUT:SEQ:DEF will be scanned each time the VT1422A
receives a scan trigger. By default, the readings taken will be sent to the Current Value
Table (CVT) and FIFO buffer. A special form of channel specifier allows changing
the default data destinations (see comments below). Any algorithms defined can also
add channels to the analog input scan list.
Parameters
Comments •
The <ch_list> parameter must contain analog input channels only.
•
Multiple occurrences of the same channel number in a ROUT:SEQ:DEF
command generate multiple occurrences of that channel in the analog input scan
list. This is useful when a particular channel needs additional settling time.
However, a scan list can contain only 32 total channels per VT1529A/B.
This means that for each VT1529A/B duplicate channel reference in a scan list,
some other channel on that same VT1529A/B must be left out of the scan.
•
When the same channel is referenced both by an algorithm and the
ROUT:SEQ:DEF command, only a single reference to the channel is added to
the analog input scan list. For each scan operation, this channel’s measured value
is made available to both the algorithm and to the FIFO/CVT.
•
Certain analog input SCPs display higher than normal offset and noise figures
if their channels are scanned just before channels on a Remote Signal
Conditioning Unit. To avoid any such interaction, a scan list should be ordered
so that all remote channels (5-digit channel numbers) appear before any
on-board channels (3-digit channel numbers).
Parameter
Name
Parameter
Type
Range of
Values
Default
Units
ch_list channel list (string) 100 - 15731 none