User guide

2. Set the configuration switches on the I/O module as outlined in Table 2–5,
Table 2–6, and Table 2–7. Also refer to Figure 2–3 for the configuration
switch location.
Table 2–5 Digital Alpha VME 4 Module Configuration Switches
Switch Setting Function
1 Closed Supplies +5 V from the VMEbus +5 V Standby signal to the time-
of-year (TOY) clock and the nonvolatile random-access memory
(NVRAM) to supplement the internal battery when the Digital
Alpha VME 4 module is turned off.
Open Does not supply power from the VMEbus +5 V Standby signal. The
internal battery will last for about 10 years with the Digital Alpha
VME 4 module power turned off.
2 Closed Enables writing of flash ROMs under program control.
Open Disables writing of flash ROMs.
3 Closed Resets the Digital Alpha VME 4 module on VMEbus Reset signal.
Open Does not reset the Digital Alpha VME 4 module on VMEbus Reset
signal.
4 Closed Digital Alpha VME 4 module is VMEbus system controller.
Open Digital Alpha VME 4 module is not VMEbus system controller.
Table 2–6 Supported Switch Settings for Digital Alpha VME 4 Modules in Slot 1
(System Controller)
Switch Setting
1 Closed
2 Open
3 Open
1
4 Closed
1
1
These switches are required to be in the indicated positions for reliable system operation during a
VMEbus Reset.
Installation Procedures 2–9