Table of Contents
Advertisement
Data lines, DI01-DI08
These are the eight Data Input/Output lines. Data is transceived on the eight HP-IB data lines as a
series of eight-bit bytes, with DIOI being the least significant bit (LSB) and DI08 being the most
significant (MSB). The meaning of each byte is arbitrary, being different for each type of instrument.
The rate of data transfer is controlled by the handshake sequence.
Handshake lines, DAV, NRFD, HD AC
These three lines control the data transfer process.
DAV, Data Valid, line is high (False - data not valid) or low (True - data valid) to indicate the validity
of the signals on the DIO lines.
NRFD, Not Ready for Data, line indicates whether the instruments receiving data are prepared to
accept that data; NRFD is either low (True - the instruments are not ready for data) or high (False -
the instruments are ready for data).
NDAC, Not Data Accepted, line indicates whether the data-receiving instruments have accepted
the transmitted data. NDAC is either high (False - the data has been accepted) or low (True - the
data has not been accepted).
Figure 3-26 illustrates a representative handshake timing sequence.
HP 8340B/41B
Operating Information
3-83
Advertisement
Table of Contents
