Chapter 2
Configuration and Startup Procedures
© National Instruments Corporation
2-5
GPIB-VXI User Manual
Setting the Servant Area Size
The servant area size is an 8-bit value (0 through 255) that indicates the GPIB-VXI servant area.
The servant area begins at the logical address following the GPIB-VXI's logical address, and
includes
N
contiguous logical addresses, where
N
is the value of the servant area size. The RM
uses the servant area of all commanders in the VXIbus system to configure the commander/
servant hierarchy, as described in the VXIbus specification. Notice that if the GPIB-VXI is RM,
the servant area size does not apply.
The servant area size switches 8 through 1 correspond to setting the GPIB-VXI servant area size
bits 7 through 0, respectively. The
ON
position corresponds to a bit value of 0, and
OFF
corresponds to a value of 1. To set the servant area size to 7 (07h), for example, set the switches
as shown in Figure 2-4.
Key
Black = side you must press down
1
2
3
4
5
6
O
F
F
O
N
7
8
Settings for Servant Area Size = 7
Figure 2-4. Example Servant Area Size Switch Setting
The servant area size switch can be overridden by the nonvolatile memory configuration as
described in the
Change Configuration Information
section of Chapter 4,
Nonvolatile
Configuration
.
Setting the Installed RAM Size
You can install up to 4M of local RAM on the GPIB-VXI. The minimum amount of memory is
512K. You can install additional memory by inserting 256K by 8-bit (Texas Instruments part
number TMS41256GU8 or equivalent) or 1M by 8-bit (Texas Instruments part number
TMS024EAD9 or equivalent) DRAM SIMM modules into the SIMM sockets as illustrated in
Figure 2-1. You must install the RAM modules in
pairs
because the SIMM sockets
accommodate
two SIMMs each
. The allowed RAM configurations and their associated switch
settings are given in Table 2-3.
