Figure 31 D20A Analog Input Peripheral Block Diagram - GE D20 Technical Overview

GE Grid Solutions
The analog input section consists of a filter and solid-state multiplexer, a variable-gain amplifier,
an integrating voltage-to-frequency converter, a programmable timer, a CPU time register and
miscellaneous support circuitry. Figure 31 is a block diagram of the analog input peripheral.
Opto
Input
Select
PPI
Opto
PGA
Gain
Ranges
Select
0.5
1
5
PGA
PTM
MCU
SYNC OPTO
50/60 Hz

Figure 31 D20A Analog Input Peripheral Block Diagram

2.4.7.1 Analog Conversion Process
Figure 32 provides an overview of the analog conversion process.
INPUT
ADAPTER
GE Information
D20A Logic Section
Filter and
Analog Mux
Voltage to
Frequency
Converter
PPR OPTO
+12V
Clock
AMPLIFIER
DIVIDER
Figure 32 Analog Conversion Process
D20/D200 Technical Overview
D20A Termination Board
Precision SWC and
Scaling Impulse
Resistors Protection
Voltage
References
Analog Input Ranges
0, +/-1, +/-5, +/-10
Temperature
Transducer
Reference
Legend
MCU.......... Microcontroller Unit
OPTO........ Optical Isolator
PTM...........Programmable Timer Module
PPI............ Parallel Peripheral Interface
PPR...........Pulse Position Resolver
Switch Mode
Power Supply
VOLTAGE TO
AUTO-ZERO
FREQUENCY
PRPI-019-3.00-10
Input
1 - 8
9 - 16
17 - 24
25 - 32
10 V
50 mA
5 V
20 mA
1 V 10 mA
5 mA
1 mA
49