User manual

Chapter 3 Software Overview
NI-DAQ User Manual for PC Compatibles 3-56 ni.com
certain restrictions on which ports can be assigned to which groups. Refer
to Table 3-7 for details.
After you assign ports to a group, the group controls handshaking of that
port. These ports are then read from or written to simultaneously by writing
or reading 8 or 16 bits at one time from the group.
You can configure the groups for various handshake configurations. The
configuration choices include a handshaking protocol, inverted or
non-inverted ACK and REQ lines, and a programmed transfer settling time.
Note
Implement buffered digital I/O via the
DIG_Block
functions described in detail in
the NI-DAQ Function Reference Online Help file.
PCI-6115 and PCI-6120 Device Groups
On the PCI-6115 and PCI-6120 devices, port 0 can be broken into two
smaller groups. These groups are referred to as group 1 and group 2. One
group is configured as an input group and the other is configured as an
output group.
Because these devices only have one digital port, a group can consist of any
combination of digital lines 0-7. For example, group 1 can be configured
as an input group containing lines 0-4 and group 2 as an output group
containing lines 5-7. Alternatively, group 1 can be configured as an output
group containing lines 1,3,5,7 and group 2 as an input group containing
lines 0,2,4,6. A portion of the eight available lines can also be configured
for group operations, with the remaining unused lines configured for
Table 3-7. Legal Group Assignments for DIO-32F Devices
Assigned
Ports
Group
Name
Group Size
(in Bits and Ports)
Port 0 1 8-bit group, one port
Port 1 1 8-bit group, one port
Port 2 2 8-bit group, one port
Port 3 2 8-bit group, one port
Ports 0 and 1 1 16-bit group, two ports
Ports 2 and 3 2 16-bit group, two ports
Ports0,1,2,and3 1 32-bit group, four ports