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INTRODUCTION
MFC DESCRIPTION
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I-E96-211A
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MFC DESCRIPTION
The IMMFC03 consists of two printed circuit boards connected
by a ribbon cable. The boards are the central processing unit
(CPU) board and the memory (MEM) board. The boards attach
to a faceplate. Visible through the faceplate are several LEDs.
The status LED, on the top left side, shows the operating mode
(run, configure, error). A column of eight LEDs, labeled CPU,
shows CPU board operating and error status. Two LEDs,
labeled MEM, show memory board operating and error status.
On board chips include UVROM, dynamic and non-volatile
RAM, VLSI and CMOS support circuitry. A 68020 microproces-
sor controls the module.
The IMMFC03 occupies two slots in the module mounting unit
(MMU) of the INFI 90 cabinet. The MMU backplane provides
module power, module bus (module to module) communica-
tion, and slave expander bus (slave module to MFC
communication).
FEATURES
MFC features include executing function codes, BASIC, and C
programs in addition to the following.
Redundancy
An IMMFC03, configured the same as the primary, provides
backup to the primary module. In a redundant setup, one
module is the primary. It performs computations, runs control
functions, etc. The other, the backup module, monitors
(tracks) the primary. The backup copies the primary control-
lers outputs, and waits in a hot standby mode. There is con-
stant communication between the primary and the backup
module. If the primary module should fail, the backup
assumes immediate control. Since the backup copied the pri-
mary's outputs, there is no break in control to the process.
NOTE: Firmware revision levels must be the same in both primary
and redundant modules. If the firmware is different and a failover
occurs, the redundant module may operate erratically.
Switch settings setup redundancy. The Installation section
explains these settings.
On-Line Configuration
On-line configuration enables users with backup MFCs to
make configuration changes (including changes to BASIC and
C programs). On-line configuration changes do not affect the
primary module or interrupt the control process. This happens
by taking the backup MFC out of the tracking mode, changing
the desired functions and putting it back in the tracking mode.
When the new configuration in the backup MFC starts up, it