Texas Instruments 990 User Manual page 18

Introduction
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Applications utilities that may be executed by users of
the network as described in Section 5. These utilities
include the following:
A downloader utility for transmitting preprocessed
files to specified secondary stations.
A remote SCI utili ty (analogous to DXlO SCI) 'to
aid in derugging tasks resident in TX5 secondary
stations.
A statistics utili ty to moni tor network acti vi ty.
Activate/deactivate utilities to provide control
over communications acti vi ti es between primary and
secondary stations.
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A supervisor call (SVC) processor that provides the
interface between the communications package and user
applications programs that use the network. The
communications SVC processor aCCesses extended
operations (XOP s) at level 15 wi th an o:f:Code of >4
D.
Calls to the SVC processor can be made from assembly
language, FORTRAN, or Pascal programs to perform the
f ollowi ng f uncti ons:
Write (transmit) information to tasks in other
stations.
Read information recei ved from another station.
Request activation (wake-up) services from the
communications pac kage.
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Canmunications tas ks attached to a procedure that
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perform the following:
Handl e all inp,lt/output (recei ve/transmi t)
operations using the communications protocol.
Control the flow of information that is initiated
by polling secondary stations.
Report errors that occur during the operation of
the communications package.
Devi ce servi ce routi nes (OS Rs) that provi de
i nterf ace between the FCCC board and the
communications package software and ,between the
board and the TX5 communications package
the
DX10
LLM
Each of these features is represented in the system diagram in
Figure 1-2.
1-6
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