DESCRIPTION AND OPERATION
INIIT03 INFI-NET TO INFI-NET TRANSFER MODULE
2 - 6
I-E96-607A
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Start-Up Control
If either INIIT02 module is restarted, it sends a message to the
other INIIT02 module so that it can take the steps needed to
synchronize itself with the restarted transfer module.
Redundancy
Redundancy requires a full set of duplicate modules (two
INNIS01 modules and two INIIT02 modules on each loop). The
secondary transfer module continuously monitors the primary.
A failover occurs when the secondary IIT module detects a pri-
mary module failure on Controlway. When this happens, the
secondary interface takes over and the primary interface is
taken off-line.
INIIT03 INFI-NET TO INFI-NET TRANSFER MODULE
The INIIT03 module passes exception reports, and control and
configuration data between a central INFI-NET loop and a sat-
ellite INFI-NET loop that have termination points within 150
feet of each other. Operation of the interface is transparent to
the user.
Blown Fuse Detection
The INIIT03 module can detect a blown fuse on the loop termi-
nation unit or module. If the loop termination unit or module
blows a fuse, or power is removed from the loop termination
unit or module, the INIIT03 module status LED turns red and
CPU LEDs three through six turn on. This feature requires an
NIS module with firmware revision E.1 or later.
Data Flow
When an NIS module receives a message, it determines the
destination of the message (in or out of its loop). If the message
has a destination on the other side of the INIIL02 interface or
the interface node itself is a destination, then the NIS module
acknowledges the message and notifies the INIIT03 module
(through the I/O expander bus) that there is an incoming mes-
sage. The INIIT03 module transfers the message from the NIS
module. If the received message contains exception reports,
these are stored in its exception report database. The interface
packages exceptions to a common destination for transmis-
sion, thus minimizing traffic through the interface.
When the local interface transmits a message it waits for
acknowledgment from the destination node. If it does not
receive an acknowledge (ACK) or busy negative acknowledge
(NAK), the NIS module initiates retries. The NIS module
attempts up to 11 retries before it marks a node that does not
