National Instruments DAQ PCI-6023E User Manual page 55

Chapter 4 Signal Connections
Name Type
ACK* Input
OBF* Output
INTR Output
RD* Internal
WR* Internal
DATA Bidirectional
PCI-6023E/6024E/6025E User Manual
Table 4-4. Signal Names Used in Timing Diagrams (Continued)
Acknowledge Input—A low signal on this handshaking line
indicates that the data written to the port has been accepted. This
signal is a response from the external device indicating that it has
received the data from your DIO board.
Output Buffer Full—A low signal on this handshaking line
indicates that data has been written to the port.
Interrupt Request—This signal becomes high when the 82C55A
requests service during a data transfer. The appropriate interrupt
enable bits must be set to generate this signal.
Read—This signal is the read signal generated from the control
lines of the computer I/O expansion bus.
Write—This signal is the write signal generated from the control
lines of the computer I/O expansion bus.
Data Lines at the Specified Port—For output mode, this signal
indicates the availability of data on the data line. For input mode,
this signal indicates when the data on the data lines should be valid.
Description
4-26 © National Instruments Corporation