Hamilton Sundstrand Company ACT2000 - Manual (Page 39)

3 OPERATING THE ACT2000
3.1 Powering Up
When 120 VDC is applied, the firmware program in the ACT2000 will
clear all system registers, retrieve all necessary operating parameters
from the electrically erasable programmable read only memory
(EEPROM), and perform an internal status check. This will also happen
after a RESET command has been received. See the flow chart in Figure
3-1 for an overview of this process.
Note: If the ACT2000 receives a SET-UP command from the
ActWiz software via the RS232 interface after these steps,
the system will transition to the Set-Up state. This state
allows the user to change the Set-Up parameters and to
download the fault file. See Section 3.8 for details.
CAUTION
Always remove the RUN command during power up. If a RUN
command is given during the Set-Up parameter download phase of
power-up, the actuator will not respond until the download is
complete and the Home position has been established.
3.2 Finding Home Position
When the status check and other steps in the Power-Up/Reset process
are complete, the ACT2000 will wait until it receives the RUN command.
At this point, the ACT2000 has no information about the position of the
actuator extension shaft.
When the ACT2000 receives the RUN command, it will initiate motion in
the homing direction. The default homing direction for the ACT2000 is
“Retract”. This means that the first movement after Power Up or Reset will
be a retraction of the actuator. The actuator will retract at the rate
specified by the Homing Velocity in the Set Up parameters (default is
0.5 in/sec) until a mechanical stop is encountered. This may be a
mechanical stop within the actuator or one in the user’s system. The
ACT2000 recognizes that a mechanical stop has been reached when the
actuator velocity drops to 0.05 in/sec or less.
CH. 3: OPERATING THE ACT2000 33