Measurement Computing Serial488/4 - Manual (Page 17)

Section 2 Getting Started
2.5
Figure 2-3. SW1 View for Addressing Mode Selection
Switch
Side
View
DOT
0
1
1 2 3 4 5 6 7 8
Dual Primary Addressing
Mode
0
1
1 2 3 4 5 6 7 8
Secondary Addressing
Mode
2.3.1.1 Secondary Addressing Mode
When Secondary addressing mode is selected,
communications with the Serial488/4 is accomplished by using the
primary bus address selected by SW 1-1 through SW 1-5 and an
additional secondary bus address. Secondary address 00 is used in
transferring command and status
information while secondary
addresses 01 through 04 are used for serial data transfers with serial
ports 1 through 4 respectively. In this mode, control of the serial
ports are multiplexed through secondary address 00,
the
command/status address, with the Port (Pn) command selecting the
desired port. D ata transfers, however, are not multiplexed as each
serial data port has its own unique secondary address.
Figure 2-4 illustrates the relationship betw een the
command/status and serial data addresses w hen using the
secondary addressing mode.