GE GFK0579B ユーザーズマニュアル

Scanning begins immediately at powerup, unless a fatal diagnostic error occurs within
the module.  At powerup, all I/O in the remote drop, except those that are presently
forced, default to Off.  I/O that are forced at the time of powerup start operation in the
forced state or value.

Following a successful powerup, a Remote I/O Scanner goes into Run mode. It remains
in Run mode unless a fatal fault or other serious problem occurs.  In Run mode, input
modules are scanned in rack and slot order.  The Remote I/O Scanner stores the input
data in its own %I and %AI memories.  These memories always contain the most
recent value for each input.

% Q

% AQ

INPUT

MODULES

OUTPUT

MODULES

REMOTE

I/O SCANNER

% I

a44977

REMOTE DROP

% AI

After the input scan, the Remote I/O Scanner scans the output modules in rack and slot
order, sending them the most recent output data from its internal %Q and %AQ
memories.

% Q % AQ

INPUT

MODULES

OUTPUT

MODULES

REMOTE

I/O SCANNER

% I

a44978

REMOTE DROP

% AI

Special–purpose  modules, such as PCM, GDS, and ADS modules, are recognized by
the Remote I/O Scanner but are not scanned for I/O data.  These modules may be
programmed to access the internal memories of the Remote I/O Scanner, where they
may deposit or acquire data.

If a fatal fault occurs, the Remote I/O Scanner goes to Stop/Faulted  mode.  The Module
OK LED is off.  In Stop/Faulted mode, the Remote I/O Scanner can communicate with
Logicmaster 90–70; it may be possible to place the module back into Run mode by
clearing all faults from its CPU Fault Table and I/O Fault Table.  This requires either a
direct programmer connection or communication with the remote drop on a multidrop
network.  It is also possible to use a Hand–held Monitor to clear all faults to attempt a
return to Run mode.  Stop/Faulted mode usually indicates a hardware fault.  If the fault
condition is not corrected, the module will not be able to return to Run mode
successfully.