Operation and Troubleshooting
Chapter 6
64
The interface has three switches on its front panel for you to use in
operating the interface (Figure 6.1).
AC POWER Switch
EXIT REQUEST Switch
TEST/RUN/RESET Switch
AC Power Switch
The AC POWER switch is a toggle switch. In the on position, this switch
connects power from the input power terminals, through the fuse, to the
power-supply circuits. With the proper voltage level of AC power
connected to the power-supply circuits through the AC POWER switch,
the interface turns on the AC POWER ON indicator.
Exit Request Switch
The EXIT REQUEST switch is a push-button switch. When you press
this switch, the interface sends out a signal to the other nodes of the Data
Highway II link that it no longer wants to be included in the logical ring.
After accomplishing this exit, the interface turns on the EXIT
COMPLETE indicator. From then on until the interface is reset, the other
nodes will not attempt to pass on the token to this node. Press the EXIT
REQUEST switch before turning off interface power or switching out of
the RUN position. If you don’t press this switch before turning off
interface power or switching out of the RUN mode, the other nodes in the
ring will waste time trying to pass the token to this node for a while
before giving up.
TEST/RUN/RESETSwitch
The TEST/RUN/RESET switch is a three-position toggle switch that
controls the operation mode of the interface. TEST and RUN are
stationary contact positions. RESET is a momentary contact position.
To change switch position, you must first pull out on the switch handle.
This feature guards against switching out of the RUN position
inadvertently.
To switch to the TEST position, first switch to RESET momentarily. In
the TEST position, the interface continuously executes self-diagnostic
tests. Each test cycle lasts approximately 50 seconds. During these tests,
the NODE TEST and MAC TEST indicators turn on and the
IN-RING/SEEKING-MEM and DUP ADDR indicators flash rapidly.
Operation Switches
