IBM Series 1 User Manual page 158

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INTEGRATED QIQITAb INPUT/OUTPYI FEATURE
INTRODUCTION
The integrated digital I/O non-isolated feature allows
user to add digital sensor
.1/0
or non-IBM devices.
feature has the following general characteristics:
the
This
• Two 16-point groups of non-isolated digital
input/process interrupt (DI/PI).
• Two 16-point groups of non-isolated digital output
(DO) •
• Four device addreses, one for each DI/PI or
DO
group.
•
•
•
All four devices prepared for interrupts with one
Prepare command.
External synchronization for each group of DI and DO.
This user attachment feature permits asynchronous data
transfers.
Interrupts can
be
initiated
by
an external sync input
(one input for each DI or DO group) or
by
a "0" to "1"
transition on a PI point.
The feature is contained on one logic card and can be
plugged into either the processor unit or the IBM 4959
I/O Expansion Unit.
Figure 5-1 is a simplified data flow of the integrated
digital I/O· feature. Refer to this figure while reading the
following sections.
Integrated Digital I/O
5-1