Lobel’s Transmitter: sixth generation AST3 weight transmitter is available in a package that weighs less than the mains transformer of the original Scale-O-Scope 25 years ago
In 1973, Bofors Electronic Transmitter(as Nobel Systems was then called), produced the world’s first microprocessor- controlled weight controller and terminal, the Scale-O-Scope.
Over 25 years after this milestone in the history of electronic load cells weighing and force measurement, Nobel’s sixth generation AST3 weight transmitter is available in a package that weighs less than the mains transformer of the original Scale-O-Scope.
The ground-breaking Scale-O-Scope was designed and manufactured by Bofors Electronics in conjunction with its patented KIS dual shear beam load cells for weighing and stock control in the meat processing industry.
The weight controller’s ability to process input and output data, communicate with other Scale-O-Scope terminals, printers and with main frame computers led to a great increase in efficiency, and typically a doubling of profitability in the plants in which they were installed.
The Scale-O-Scope weighed 30kg, used an Intel 4040 4-bit processor with 4k memory, and featured 16-bit A/D conversion, a resolution of 1 in 30,000, and a communication speed of 300 baud.
It boasted digital scaling and set up, keyboard input and a dot matrix digital weighing display with alpha-numeric presentation of weight and data.
The trend since then has seen the extensive use of microprocessor power to give greater flexibility, higher resolution and accuracy, faster speed, easier setting up, smaller size and lower cost.
More than twenty-five years on from the Scale-O-Scope, E-2-TAD weighs in at 3kg, has three microprocessors, a resolution of one in half a million and communicates with RS232, 422 or 423 at 9600 baud .
It is CE EMC compliant, and has OIML (weights and measures) certification for accuracy class III for 10,000 divisions.
Now, the sixth generation AST3 goes one stage better, with an internal resolution of 1 in 8 million (23 bit) using a patented Sigma-Delta A/D conversion technique and communicates on RS485 at 115k baud using modbus protocol.
Analogue outputs of 0-10V, 0-2mA or 4-20mA are standard.
Communication speed is 380 times greater than the original Scale-O-Scope and resolution 260 times greater.
There are no potentiometer adjustments – all scaling is carried out and stored digitally and can be carried out via the front panel keypad or downloaded via the serial port using windows-based software.
Filtering can be pre-programmed to suit the dynamics of the application and is “adaptive” – that is, it has a wide bandwidth and fast response for large weight changes and shuts itself down to a narrow bandwidth for small changes.
The AST3 can also be connected via a modem to allow remote diagnostics and maintenance of the weighing system.
The unit is fully CE compliant to meet the latest EMC and low-voltage directives.
All this comes complete with a digital display in a DIN rail-mounted package that weighs less than 0.5kg.
Small is definitely beautiful – the new AST3 weighs approximately 1/60th of the original Scale-O-Scope of 1973.
This is exemplified by Nobel’s microprocessor-based weighing instruments, the E-2-TAD digital weighing controller and the most recent AST3 weight transmitter.
Watch the video related to modbus
This video describes how to configure and connect a Matrikon OPC Server for Modbus to a device.
Man great work,its relly admirable,I was wondering if i can get this project to have an idea on how to work with citect scada,iam a beginner i hope ill get better like you sumday
,Best of luck for the future,You have a fan of your work.
This is a great project. Will you be so kind to share the project files with me. I want to do some home automation, and this would be ideal.
Thanks for posting your video. It is really good to see pic micro projects.
I am new to pic micro’s and already admire their power.
Thanks
Ivan
Slavery is outlawed in most countries. You'd better watch what you say.
Modbus is a popular (and cheap/easy) protocol that all Schneider/Modicon PLCs speak. It is cheap because it is in the public domain and everyone has written drivers using that. Twidosoft and Twidosute (free downloads) botj contain Modbus drivers that can be configured, verified, and run with the Modicon PLCs.
Modbus is the protocol developed by Modicon to talk with a
RTU (Remote Terminal Unit)
Your question does not make sense…….
never heard of such a thing
An interface establishes a connection or boundary between the software and hardware. Say, if you want to access information about RAM an interface would provide the programming required to get the information displayed.
Protocol provides a method to acquire the communication. When talking RS232/Rs485 you are identifying converters which manipulate modulation.
For the quality of connectivity over distances you are indeed on the right track. RS232 coupled with Modbus will give you an overall better quality because the transmittion is sent over as plain form (text). Modbus is peer-to-peer but can perform over point-to-point and multidrop networks.
The hardware and wires are the same, Ethernet commonly uses Cat 5E wire and RJ-45 8 conductor connectors. They are the ones that look like an overgrown modular phone plug.
Modbus is a communications protocol, and would not be the same protocol as what your home or office network is using to communicate between computers and printers even though it is Ethernet hardware and wiring.
Modbus would commonly be used between a PLC and other devices such as an engine, turbine or generator controller (Many such devices exist) to gather data and take it back to a central HMI (Human-Machine Interface) or alarm annunciator. Some such devices can be controlled using Modbus as well.
Modbus allows for communication between many devices connected to the same network, Not just computers, but different devices
Take a look at the wiki for exaples and more detailed info
http://en.wikipedia.org/wiki/Modbus
a "Modbus Splitter" allows two or more Modbus Masters to communicate with a network of one or more Modbus Slaves: Thus "Splitting" the network and allowing multiple Masters to communicate with a single network of Modbus Slaves.