DESCRIPTION AND OPERATION
I/O SECTION
I-E96-207A
2 - 3
unique in that it retains whatever information it has even when
power is lost. This is possible because of the back up batteries
that keep the memory active if power is lost.
The modules memory is divided as follows:
•
48K bytes of Read Only Memory (ROM) - 04 version
•
32K bytes of Read Only Memory (ROM) - 03 version
•
4K bytes of Random Access Memory (RAM)
•
2K bytes of NVRAM
Logic Power
Logic power (+5 VDC and
±
15 VDC) drives the COM circuits. It
connects through the top 12-pin card edge connector (P1)
shown in Figure
. P3 su24 VDC to operate the ana-
log output circuits.
I/O SECTION
The I/O section allows the processor to interface with the analog
and digital inputs and outputs. The I/O section contains A/D or
D/A, default output switch selections. It also contains the ana-
log output mode selection (voltage/current) and the status LED.
The I/O section contains the analog control station interface
and module bus interface.
Analog I/O
The COM can input four separate analog signals (1 to 5 VDC),
and output two separate analog signals (1 to 5 VDC and 4 to 20
mA). The module accepts analog inputs that are either single
ended or differential voltages. The COM output mode is select-
able: current or voltage. Figure
shows typical analog input
and output circuits.
Figure 2-1. Controller Module Block Diagram
LOGIC POWER
MODULE STATUS LED
MODULE BUS
SERIAL LINK (SAC)
ANALOG INPUTS (4)
DIGITAL INPUTS (3)
ANALOG OUTPUTS (2)
DIGITAL OUTPUTS (4)
T00140A
PROCESSOR SUPPORT
(MODULE BUS INTERFACE,
SERIAL LINK INTERFACE)
MICRO-
PROCESSOR
ROM
RAM
ADDRESS
SWITCH
NON-VOLATILE
RAM
OPTICAL
ISOLATION
D/A
CONVERTER
A/D
CONVERTER
THRESHOLD
DETECTION
DRIVERS
VOLTAGE/CURRENT
SWITCHES
INPUT
CONDITIONING
ANALOG OUTPUT
DEFAULT SWITCHES
OPTICAL
ISOLATION
P1
P3
P2
