Bailey Infi 90 INPCI01, Instruction, Page: 15 / 43

INTRODUCTION
I-E96-620A 2 - 1
SECTION 2 - DESCRIPTION AND OPERATION
INTRODUCTION
The Plant Loop to Computer Interface (INPCI01) enables a host
computer to interact with all nodes on an INFI 90 Plant Loop.
The Plant Loop is a unidirectional serial data highway that all
nodes (and other data users) share. The PCI provides an
RS-232-C serial interface that links the Plant Loop to the host
computer. This section covers the functional operation of the
modules that make up the PCI.
INTERFACE OPERATION
The INPCI01 consists of three modules:
•
Loop Interface Module (INLIM03)
•
Point Table Module (INPTM01)
•
Serial Interface Module (INSIM01)
These modules reside on a dedicated module bus. Figure 2-1 is
a block diagram showing how each module functions as part of
the interface.
Loop Interface Module INLIM03
The Loop Interface Module is the communication interface to
the Plant Loop. The LIM sends and receives messages from
Figure 2-1. Functional Diagram of the INPCI01 Modules
PLANT LOOP
TERMINATION
UNIT
HANDLE
PLANT LOOP
PROTOCOL
ACCEPT
MESSAGES
ADDRESSED
TO PCI
INTERPRET
LOOP
MESSAGES
POINT
TABLE
HANDLE
DIAGNOSTIC
PORT
REPORT
ROUTES
SPECS OF
POINTS
READ BY
COMPUTER
BUFFER OF ONE
COMMAND WHICH
REQUIRES
COMMUNICATION
WITH MODULES IN
ORDER TO REPLY
INTERPRET
COMMANDS
CHECK
COMMAND
FORMAT
SEND
REPLIES
COMPUTER
INTERFACE
TERMINATION
UNIT
TO
PCU,
OIS,
PCI
LOOP
INTERFACE
MODULE (LIM)
SERIAL
INTERFACE
MODULE (SIM)
POINT TABLE
MODULE (PTM)
FORMAT
ERRORS
REREAD
REPLY CODE 9
TO FIRST CIU
RESTART
T00405A
MODULE BUS
TO
DIAGNOSTIC
TERMINAL
TO
COMPUTER