Keysight Technologies VXI bus 75000 C Series, Service Manual, Page: 23 / 130

Keysight E1406A Command Module Service Guide 23
Command Module Configuration Verification Tests
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Primary GPIB address (set with the GPIB Address switch)
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Secondary GPIB address (derived from the Logical Address)
Instruments are located by the GPIB address. For example, Figure 2-2 shows a
typical GPIB Address. The GPIB Primary Address is set with the GPIB Address
switch (switch 6 in Figure 2-1). However, the GPIB Secondary Address is derived
from the Logical Address switch setting using the relationship:
GPIB Secondary Address = Logical Address/8
Thus, in Figure 2-2, since Logical Address 64 is set (with the Logical Address
switch), the GPIB Secondary Address = 64/8 = 08. Note that there are no
switches to set the Secondary GPIB Address.
Commander/Servant Areas
In a VXIbus system, the servant area identifies the modules (servants) that are
controlled by other modules (commanders). The Logical Address
switch sets the command module as the resource manager and is used with the
command module Servant Area switch (Switch 5 in Figure 2-1) to determine the
servant area of the command module using:
Servant area = (Logical A1) through (Logical A
Servant Area switch setting)
See Figure 2-3 for an example commander/servant hierarchy.
The "divide logical address by 8" process to get the IEEE-488
secondary address is the Keysight implementation of VXIbus
addressing using the Keysight E1406A command module. Other
manufacturers may use different methods.
The GPIB Secondary Address for the Keysight E1406A command
module is always 00, regardless of the logical address set.
Figure 2-2
Example: GPIB Address vs Logical Address