User`s guide

–61–
Product Information
Specifications
Basic port
interface
The following limitations and capabilities apply to the Basic port
interface (Ports
1–8
) of MasterSwitch plus:
• Pins 3, 5, and 6 are open collector outputs which must be pulled
up to a common referenced supply no greater than
+40 V
dc. The
transistors are capable of a maximum non-inductive load of
25
m
A
dc. Use only Pin
4
as the common.
• The output at Pin
2
generates a
LO
-to-
HI RS-232
level when the
device is signaling an On Battery condition. The pin is normally at
a
LO RS-232
level.
• The MasterSwitch plus unit may be signaled to shut down the
UPS
by applying a
HI RS-232
level to Pin
1
for
4.5
seconds. Shutdown
is also dependent on the
UPS
status and the MasterSwitch plus
shutdown mode (see“MasterSwitchplus Properties” on page 12).
Basic port pin
assignments
Continued on next page