PLC DEMO SYSTEM
The PLC board is a complete Industrial Process Control Demo system. It has four
isolated input channels and four isolated output channels. Total system accuracy
is 0.05%. The input channels have 24 bit resolution (using AD8220 IN-AMP + AD7793 Sigma Delta
ADC), each channel can be configured to accept a wide variety of input signals,
from 4-20ma current loops to to high voltage inputs 0-5, 0-10v, +/-5v, +/-10v.
It can also accommodate RTD/TC inputs. The output module has 16 bit resolution
(AD5422) which has an integrated output driver and built in fault detection and
protection. The AD5422 has the following programmable output ranges, 4-20ma,
0-5v, 0-10v, +/-5v, +/-10v. Each range has 16 bits of resolution. The complete
design uses ADI isolation technology, processors and power management products,
allowing customers to evaluate the whole signal chain.
PLC DEMO SYSTEM
Features
- Inputs Selectable: 0-20mA, 4-20mA, 0-5V, 0-10V, ±5V, ±10V, RTD, TC
- Outputs Programmable: 0-20mA, 4-20mA, 0-5V, 0-10V, ±5V, ±10V
- FOUR ISOLATED 24 BIT ANALOG INPUT CHANNELS
- AD7793 24 Bit
Sigma Delta ADC, 40nV Noise - ADR02 Precision
5V Ref - AD8220
Instrumentation Amplifier, >80db CMRR - ADUM5401
isoPower integrated, isolated dc-to-dc converter 500 mW output power
- FOUR ISOLATED 16 BIT ANALOG OUTPUT CHANNELS
- AD5422 Single
Channel, 16-Bit, Serial Input, Current Source & Voltage Output DAC - 0.05% Total Unadjusted Error (TUE)
- Single Chip Solution
- Open and Short Detection and Protection
- AD5422 Single
- POWER/INTERFACE/CONTROL
- ADI ARM 7 ADUC7027
- ADP3339 High
Accuracy Ultralow Iq, LDO - ADM3251 Isolated
Single Channel RS-232 Line Driver/Receiver
PLC Total Solution Diagram
Documentation
The following Technical Note describes the PLC reference
design/evaluation system.
To download the Documentation, select the link
below
PLC Reference Design/Evaluation System, Industrial Process Control
Evaluation System (pdf,
1,109,925 bytes)
Evaluation System (pdf,
1,109,925 bytes)
Source Code
The source code was written for ADUC7027 to perform basic
communications with on board data converters. The description of files included
are:
communications with on board data converters. The description of files included
are:
- main.c - Implements data comms between PC and PLC Design Board.
- plcbios.c - Contains the drivers for ADC/DAC communications.
- plcbios.h - Header File for PLCBIOS.C/ADUC7027
- AD7793.h - Header File for AD7793 ADC.
Download Source Code
(zip, 6,430 bytes)
