Specifications

Alto 818 Installation and Operation
2-6 P/N 66109074001 Rev. D
MAIN PCA SWITCHES
The Alto 818 has three switches mounted on the main printed circuit assembly: The reset switch
(S1), the battery switch (S2), and the goof switch (S3). The location of these switches is shown
in Figure 2-3.
Reset Switch (S1) The reset switch is a momentary-contact, push-button switch used to reset
the microprocessor. In the event that the VITAL FUNCTION LED does not blink, indicating the
microprocessor is not functioning properly, this switch is used to restart it. Resetting the
microprocessor with this switch will not change any of the system operating parameters. It will,
however, set the anti-passback status of all users to UNKNOWN and cancel operator override
commands such as UNLOCK or RELOCK.
Battery Switch (S2) The battery switch is a slide switch used to connect or disconnect the lithium
battery circuit. This switch is placed in the OFF position before the ACU leaves the factory, and
must be placed back in the ON position when the ACU is installed. The battery switch is also used
to turn off the battery circuit when changing the lithium battery or when placing the ACU in storage.
When there is no power coming from a system supply, turning off the battery will cause loss of
all system data.
Goof Switch (S3) The goof switch is used to gain access to the system commands in the event
that the password(s) for the operator(s) with authorization rank A have become lost or forgotten,
or no rank A operators are available in an emergency situation. Operating the goof switch causes
the user 1 password to revert to NEW with a rank of A and the terminal baud rate to be set to the
default of 300 baud.
The goof switch is operated by simultaneously pressing and holding the reset switch and the goof
switch, then releasing the reset switch before releasing the goof switch.
LED PANEL
An LED panel is mounted on the main PCA and is visible through a cutout on the ACU cover. Eight
LEDs, RELAY 1 through 8, illuminate when their associated door lock relays are activated. Two
LEDs indicate transmit (TX) and receive (RX) activity at the terminal port, and two more indicate
activity at the host port. The remaining LED (VITAL FUNCTION) flickers to indicate normal
microprocessor operation.