Keithley KPCI-3101 Series, User Manual

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2-18 Principles of Operation KPCI-3101 — KPCI-3104 Series User’s Manual
Combining or splitting logical channels
DriverLINX supports a software extension to Logical Channel addressing that allows applica-
tions to combine adjacent Logical Channels into a single channel or split a Logical Channel into
smaller addressable parts. For instance, applications can address individual bits on the digital
I/O ports or read and write multiple channels with a single operation.
In DriverLINX, “Native” units refer to the hardware-defined digital channel size (8 bits for
KPCI-3101–4). When using extended Logical Channel addressing, DriverLINX groups digital
bits in units defined by a size code and then assigns consecutive channel numbers starting from
zero.
For example, with three 8-bit ports the following channel addresses are supported for each size
code.
Refer to DriverLINX Digital I/O Programming Guide for information and limitations of this
extended channel addressing function.
Using single value and continuous digital input
DriverLINX uses the Digital I/O Subsystem for single value outputs. For continuous digital
input, DriverLINX uses the Analog I/O subsystem (see “Specifying digital input lines in the ana-
log input channel list,” starting on page 2-4).
• Single value operations stop automatically when finished; you cannot stop a single value
operation.
•
Continuous digital input takes full advantage of the capabilities of the KPCI-3101–4 Series
board. Program the digital input lines of Ports A and B as Analog Input Channel 0; enter the
inputs through the DriverLINX A/D subsystem. You will assign a special gain code to this
channel to distinguish it as digital. You can specify parameters such as clock source, scan
mode, and trigger source for the digital input operation. Refer to
page 2-4 for more informa-
tion on specifying digital input lines for a continuous digital input operation. Refer to Using
DriverLINX with Your Hardware, provided with DriverLINX, for information about this
function.
Table 2-6
Extended channel addressing of digital I/O channels using DriverLINX
Unit Channels Address (dec) Address (hex)
native 0..2 0..2 0..2
bit 0..23 4096..4199 1000..1017
half nibble 0..11 8192..8203 2000..200B
nibble 0..5 12288..12293 3000..3005
byte 0..2 16384..16386 4000..4002
word 0..1 20480..20481 5000..5001