1. Case Study Computer Controlled Radiation Monitoring System
Prepared by: A.siminfar, A.bahrami
Presented By : Abbas Bahrami
Health physics officer & Network Administrator
Nuclear Research Center for Agriculture & Medicine
Atomic Energy Organization of IRAN

2. 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.

3. Requirements Area radiation monitoring System
Single area radiation Monitor (stand alone)
Area radiation monitoring System

4. 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

5. 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

6. 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)

7. Area radiation monitor (Terminal) (Implemented system)
A terminal mounted in waste room

9. Two Area Monitors installed in the Hot Cell Laboratory of Cyclotron

10. Top 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
Front View

11. Block Diagram of an Area Radiation Monitor

12. 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

13. 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

14. 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

15. 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

16. Main Page of Radiation Monitoring System’s Software

17. Page2 of Main Pages

18. Monitoring of off line data

19. Monitoring of Off Line data by Graph

20. Setting the Alarm Level of Terminals

21. Setting the Alarm & Warning Level of a Terminal

22. Networking of The System
Using RS485 Standard

23. RS485 Standard
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

24. Advantages Simple and low cost hardware
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

25. 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

26. Development for future
IP-Based (in progress)
Web Based Monitoring (Connecting Monitors directly to Internet)

27. An IP address is assigned to each terminal’s converter
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

28. Ethernet
IP Based Area Radiation Monitoring System

29. Hardware modification
IP Based System
Hardware modification
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

30. Software modification
IP Based System
Software modification
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

31. Advantages In Existence of LAN, no extra cabling is needed
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

32. Disadvantages HUBs/Switches is needed for networking
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

33. Web Based Monitoring System
Web pages must be designed in terminals
Terminals must support TCP/IP protocol

34. 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

35. Thank you