Jumper Settings - Xycom XVME-976/202 Manual

XVME-976 Adapter Module

Jumper Settings

Function
Termination
Bus Size
Termination
The 10Base2 input (BNC) can be terminated on the XVME-956/411 card. This
eliminates the need for the TEE fitting + BNC terminator at the end of the line, and
is very convenient for simple two or three node nets. The on-card termination should
not be used if the Ethernet cabling is subject to frequent change, as it is easy to for-
get that a card is terminated internally. The internal termination is enabled by setting
the shorting jumper on jumper block W1 in the UP position. Setting the jumper to
the DOWN position disables the internal termination.
Bus Size Selection
The XVME-956/411 can work with 8 and 16 bit CPUs. Bus size is normally se-
lected automatically by sensing the voltage on the PC/104 bus J2 connector pin 34.
This is a 5V line on the AT part of the bus connector. If 5V is sensed on this line, an
AT type CPU is assumed, and 16 bit bus transfers are used.
If the shorting jumper on jumper block W2 is placed in the left hand position, auto-
matic bus sizing is enabled. If the shorting jumper is placed in the right hand posi-
tion, the XVME-956/411 is forced into the 8 bit mode.
5-2
Table 5-1. Default Jumper Configuration
Default Jumper
Disabled
Auto
Position
W1 Down
W2 Left