46033-1098 <90-00011>
P
AGE
3
GENERAL DESCRIPTION
CIRCUIT DESCRIPTION
T
he 46033 E-System Adapter functional schematic is shown
in Fig. 1.
CPU (Central Processing Unit)
The major component of the 46033 is its on-board 8-bit micropro-
cessor (CPU). The CPU controls all functions of the module
except for the start-up routine and functional programming.
When power is applied to the module, the CPU reads the
EPROMs to set itself for the appropriate logic functions it is to
perform.
The CPU translates data between the two different system
protocols to interface the 46020 Multiple Alarm Processor of the
460 ACS to standard E-Systems. A secondary data bus output
from the CPU drives a green LED labeled DATA XMT that
lights when the unit is transmitting data to the E-System.
Data Control
For data input/output, the module has an Asynchronous Com-
munications Interface Adapter (ACIA) that bi-directionally
controls data to be handled by the CPU. When the unit receives
a block of data that constitutes a command or routine request,
the ACIA sequences the data to the CPU using random access
memory (RAM) as a buffer to temporarily store the data. When
the CPU goes idle, the ACIA activates and dumps the next data
block from the RAM to the CPU for translation and output.
Logic Functions
The logic functions of the 46033 accomplish the task of data
protocol translation and conversion. The Erasable/Program-
mable Read-Only Memory (EPROMs/Firmware) on its circuit
board provide nonvolatile memory to configure the CPU at
startup and program it for the appropriate logic functions. The
-11 Option
16 points (normally, the first subgroup of group four)
The 46033 is a plug-in PC board module that fits into any
400-type or similar equipment housing. The front panel has an
indicating LED, a subassembly cutout, a carrier test switch, and
jacks. The 46033 is also equipped to accept subassemblies for
data communications.