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Publication No. 980938 Rev. K
Model T940 User Manual
Astronics Test Systems
Installation 2-3
Figure 2-3: Digital Board (DB) Switch Locations
CAUTION
Switch settings shown in Figure 2-2 are for example only and are not
particularly what your board should be set to. Refer to the text for
proper switch settings.
Logical Address Selection
The VXI chassis Resource Manager identifies units in the system by the unit’s
logical address. The VXI logical address can range from 0 to 255. The
exceptions are addresses 0 and 255. Address 0 is reserved for the Resource
Manager. Address 255 is used for dynamic configuration.
The logical address of the DRM can be statically or dynamically configured.
SW1
, an eight position DIP switch located on the DB (Figure 2-3) is used to
assign the logical address. Refer to Table 2-1.
A switch setting between 1 and 254 will establish a static logical address of the
binary encoded value. A switch setting of 255 will place the DRM in a dynamic
logical address mode where the final logical address is assigned by the resource
manager. A switch setting of 0, while normally invalid as a selection, also will
place the DRM in a dynamic mode avoiding configuration conflicts with Logical
Address 0.
The DRM is shipped in the dynamic configuration with a switch setting of 255.
Table 2-1: Logical Address Selection
SW1
Position
8
7
6
5
4
3
2
1
Signal
LA0
LA1
LA2
LA3
LA4
LA5
LA6
LA7
Switch position 8 through 1 corresponds to bits 0 through 7 of the logical
Do not
adjust SW3
VXI Connector
VXI Connector