We have with us RS232-RS485 Integrator which was on Modbus RTU protocol earlier. will this integrator support the J-bus protocol.

Please give the solution as early as possible.

[email protected]

 

Hello shyam;
Jbus and Modbus are very similar, there is only a slight variance in the addressing scheme (J-bus registers start at address xxxx1, modbus addressing starts at address xxxx0. They support the same functions (as applied by the manufacturer of your slave) and the same configuration.

Here is a quote you can look up on the following webpage:
http://www.northbt.com/support/faq/000013
" The ModBus protocol was developed as an industry standard by Gould, but due to a copyright problem the protocol entered in to the public domain. It has been used by a multitude of manufacturers under the name of 'JBus'. Therefore, ModBus and JBus are identical protocols, only the name is different. If the product is JBus or ModBus compatible then it can be communicated with using the North JBus driver. What has to be determined is how a particular manufacturer has applied the protocol to their system - which registers have values in, and how are they stored. "

To my experience, we have used Modbus and J=bus slaves on the same network without any problems.

Hope this helps,
Daniel Chartier

 

Hello
does every body know how can we use JBus protocol with a PLC? (a Siemens PLC for example) is there any special module for that? does it need a program?

(I a very new to this as you see! please guide me)

 

Hi M.M.Sh,

Siemens have different PLC´s, S7-1200 is a micro PLC with a programmable serial port, for S7-300/400 I think that you have to buy a serial interface card CP341/CP441.
Most likely a gateway is easier and cheaper to use for S7-300/400. There are many gateway suppliers, I work for one, HMS (Anybus).

For Profinet:
http://www.anybus.com/support/support.asp?PID=345&ProductType=Anybus Communicator

For Profibus:
http://www.anybus.com/support/support.asp?PID=104&ProductType=Anybus Communicator

With a gateway solution, Anybus, you will configure the serial side to read/write to J-Bus/ModbusRTU and if changing the higher level network (PLC) to other than Siemens, you can re-use the configuration.

for more info, contact [email protected]

Patrick L

 

For siemens PLC you need S7-441-2 or S7-341-1 card (serial communication) with the selected hardware type (RS232, RS485, RS422 or TTY) connector and a modbus slave or a modbus master driver. The driver plugs into the back of the CP card and handles all modbus communications in combination with a function block provided with the driver.

Hope ths helps,
David