Figure 4: D20 VME chassis - VME bus backplane and D20M+ termination panel
WESTERM D20VME -
VME Bus Backplane
D20 VME Chassis
The chassis-mounted power supply modules are switch-mode converters that provide
output power for the D20MX processor board, VME cards, modems and D20 Peripheral I/O
modules, as required. A redundant power supply can be installed to provide fail-over
protection to ensure continuous power to the D20.
If you have an extended system with more than five peripherals, the chassis-mounted D20
power supply is not adequate. In this case, you need to install an external power supply.
Table 5 lists the standard power supplies that are available. Other power supplies are
available for specific requirements. Contact GE Digital Energy for details.
Table 5: Available power supplies
GE part number Input
20 to 60 V DC
20 to 60 V DC
100 to 300 V DC or 85 to 264 V AC +5 V, 7 A; +12 V, 2 A; -12 V, 1 A; 24 V DC, 3 A
100 to 300 V DC or 85 to 264 V AC +5 V, 7 A; +12 V, 2 A; -12 V, 1 A; 48 V DC, 1.5 A
Ensure your D20 power input is externally protected for over-current; otherwise damage to
the D20MX may occur. The required fuse rating depends on the power consumption of
The D20 available power supplies, listed in Table 5 are equipped with two field replaceable
fuses.; see Figure 5.
+5 V, 7 A; +12 V, 2 A; -12 V, 1 A; 24 V DC, 3 A
+5 V, 7 A; +12 V, 2 A; -12 V, 1 A; 48 V DC, 1.5 A
CHAPTER 1: BEFORE YOU START
D20MX HARDWARE USER'S MANUAL