Transcript Introduction

Case Study
Computer Controlled Radiation
Monitoring System
Prepared by: A.siminfar, A.bahrami
Presented By : Abbas Bahrami
Health physics officer & Network Administrator
[email protected]
Nuclear Research Center for Agriculture & Medicine
Atomic Energy Organization of IRAN
ALARA
• Radiation protection is an important rule in
practices that involve radioactive
sources.
• For reducing the absorbed dose of
personnel, the working areas must be
under control.
• For this, the health physics officer must be
able to monitoring all hot areas.
Requirements
– Single area radiation Monitor (stand alone)
– Area radiation monitoring System
• Single Area Radiation Monitor
 Measures the environment dose rate around the
detector
 Displays the measured value on a display board
 More sensitive than other dose monitors (e.g.
Personal dosimeters
• Area Radiation Monitoring System
 Consists of several single area radiation
monitors, that is controlled through a central
unit
 Communication between monitors and central
unit is carried out by a network
 Measured values on monitors are displayed in
central unit (on line)
 Data is stored in central unit for further uses
Computer Controlled Area Monitoring System
Consist of:
•
1- Area radiation monitors (called as terminals)
•
2- Central control unit (PC)
•
3- Network
RS485 (Design a network and define a protocol)
Area radiation monitor (Terminal)
(Implemented system)
A terminal
mounted in waste
room
Two Area Monitors installed in the Hot
Cell Laboratory of Cyclotron
Top View
Front View
1- Normal State LED
2- Warning LED
3- Alarm LED
4- Audio Alarm ON LED
5- Audio Alarm OFF LED
6- Set Alarm ON/OFF
7- Pulse LED
8- Setting Display Un
9- Display Count/Sec LED
10- Display Dose Rate LED
11- Display 7_SEGs
12- CAT5 Connectors
13- CAT5 Connectors
14- Fuse
15 – Detector Probe
Block Diagram of an Area Radiation Monitor
Connection of Area Radiation Monitor to
BUS-RS485
 Send line ADM485 is enabled by the Microcontroller for
releasing the BUS after sending data
 Using ADM485, Microcontroller’s serial data in TTL format is
converted to RS 485 format
Terminal 1
. . . .
Terminal 16
Monitor
Copmputer
Interface
Main Software
Keyboard
Terminal 1
2
Interface
Data bus
Digital I/O
Terminal 2
Terminal n
. . . .
Send
Receive
2
 Terminals connected to the central computer via an interface
module
 Communication between the terminals and interface is carried
out by two transmission lines for send & receive, using RS485
standard
Software of Area Monitors (Terminals)
 Has
been Designed for 8051ED2 Microcontroller by assembly
language
 Has been designed for :
• Count and Process the output pulses of the detector
• Calculate the dose rate regarding to pulse rate
• Display the dose and count rates
• Alarm in high dose
• Communication with the Interface
• communication with user by some micro-switches and display board
Central Control Unit
•
•
•
•
Designed By VC++, so it is object oriented
Can be run with Windows
is user friendly
Has following duties:
•
•
•
•
Communicate with terminals via interface
Show the dose rate of terminals On line
Save the data in DB ( *.mdb Access format)
Show off line data in daily, monthly and yearly
graphs
• Make Reports
• Adjust Alarm level of terminals
Main Page of Radiation Monitoring System’s Software
Page2 of Main Pages
Monitoring of off line data
Monitoring of Off Line data by Graph
Setting the Alarm Level of Terminals
Setting the Alarm & Warning Level of a Terminal
Networking of The System
Using RS485 Standard
RS485 Standard
Terminal 1
2
Interface
Terminal 2
Terminal n
. . . .
Send
Receive
2
 Terminals is connected to the central computer via an
interface module
 The communication between the terminals and interface is
carried out by two transmission lines for send & receive, using
RS485 standard
 Interface module controls the network and acts as a BUS
master
Advantages
RS485 Standard
 Simple and low cost hardware
(no Hub, switch and Ethernet card are needed )
 Distance between terminal and central control can be
increased (up to 5 Km)
 Possibility of saving data in the interface when the computer
is off
Disadvantages
RS485 Standard
Need to design and apply a suitable protocol
A hanged terminal may occupy the BUS
(in the end of communication between a terminal and Interface,
terminal must release the BUS)
A central computer is required for connecting to
the terminals
(terminals can not be connected to Ethernet directly)
In Existence of LAN, another cabling is need
for this system
An interface module for connecting the BUS to
computer is required
Development for future
• IP-Based (in progress)
• Web Based Monitoring (Connecting Monitors directly
to Internet)
IP Based Area Radiation Monitoring System
• Using serial to TCP/IP converter (Network
Enabler for Serial Device), monitors are
connected to LAN and controlled by a central
computer
• Without considering converter, each terminal is
the same as the last one.
• An IP address is assigned to each terminal’s
converter
• Data is sent in the format of TCP/IP from
central computer, the converter extracts the
pure data and pass it to the terminal’s
microcontroller
Ethernet
IP Based Area Radiation Monitoring System
Hardware modification
IP Based System
Hardware modification in the IP-Based
System regarding to RS485:
• Add a Network enabler device (Serial To TCP/IP
Converter) in each terminal instead of TTL to RS485
converter
• No need to an Interface module
• Use HUB/switches in network
• Ethernet card in control computer
Software modification
IP Based System
Software modification in the IP-Based
System regarding to RS485:
• In the Terminal software:
Network Enabler (Converter) in each terminal causes:
• A terminal receive only its own data
• A terminal send data without any request - data collision
do not happen
• In the Central Computer Software:
Connecting to the Network Enabler Devices instead of
interface that was carried out by serial port in the last one
Advantages
IP Based System
• In Existence of LAN, no extra cabling is needed
• TCP/IP is the transmission protocol, no new protocol in
needed
• High reliability of the network
Disadvantages
IP Based System
• HUBs/Switches is needed for networking
• Network Enablers for Serial Device is Needed
• To connect a computer in the LAN directly to a
terminal, a software must be installed in the
computer
• Terminals can not be directly connected to
internet
Web Based Monitoring System
 Web pages must be designed in terminals
Terminals must support TCP/IP protocol
Advantages
Web Based System
• From all over the world each terminal can be
accessed via internet
• Central computer can be anywhere
• Protocol and network hardware are standard
Thank you