PWRS-0026 User Manual
Page 17 of 19
VIII. Handshake Mode Operation
The following describes the internal logic and variables used in
Handshake Mode. The standard NT UPS functionality is used in addition
to the following logic. A driver and DOS utility are provided with this
functionality.
On power up, UPS_ENABLE = 0
After NT completes boot, set UPS_ENABLE = 1
POWER_OK = 1 until power detection circuit determines power loss, then
POWER_OK = 0
FAIL_MODE = 1 if POWER_OK = 0 for more than FAIL_TIME
If FAIL_MODE and UPS_ENABLE = 1, provide UPS battery power until
time > UPS_TIME or REMOTE_UPS_SHUTDOWN is received.
On standard NT shut-down, UPS functionality is disabled.
Definition of terms:
UPS_ENABLE
Internal register which controls enable
state of UPS
POWER_OK
Internal register which indicates status of
incoming power line
FAIL_TIME
Time that a no power condition is
detected until FAIL_MODE = 1
UPS_TIME
Time that power is supplied after
FAIL_MODE = 1
REMOTE_UPS_SHUTDOWN
COM port handshake signal from CPU
to shut down supply. Default time delay
is 2 minutes.
