PLC Communication with DCS

Dear All, A very Good morning to all of you,
I was new to this forum and also new in the Instrumentation industry.
I have some problems related to PLC DCS communication request to clarify the same.
I have a control system distributed in three levels Level I is having DCS, Level II is having Main PLC and Level III is having micro PLCs. I have to make communication in between level II to level I (Modbus)and also Level II to Level III(Profibus). Now i was having doubts regarding I/O list of Level II, whether i have to consider all the i/Os of Level III in level II I/O list if the communication is through profibus. and also with level I. Or it will directly communicate with all the levels on communication bus? Also can i read and write any command from level I (DCS) through this communication. waiting for your valuable feedbacks.

Dear dnyaneshnawale,

There are several possible solutions. One solution could be to use gateways between the different levels.
Between level I and level II, a Modbus slave to Modbus slave gateway coulde be used. Such as:
http://www.anybus.com/support/support.asp?PID=234&ProdType=Anybus X-gateway
Between level II and level III, a Modbus slave to Profibus slave gateway could be used, if there is a Profibus master present on level III.
http://www.anybus.com/support/support.asp?PID=185&ProdType=Anybus X-gateway

If there is no Profibus master present on level III, you would need a Modbus slave to Profibus master gateway, such as:
http://www.anybus.com/support/support.asp?PID=140&ProdType=Anybus X-gateway

If you would like to have more information about the gateway solution, let me know ([email protected]) or contact our distributor in India.

U L Electrodevices Pvt. Ltd
Nirman Classic, III Floor
Katraj-Kondhwa Road
Pune
411 046
India
Tel: +91 20-26962125
Fax: +91 20-26962079
Email: [email protected]
Webpage: http://www.ulepl.com


//Patrick Lansdorf