I need to read and process some variable from a Quantum PLC to another Quantum PLC. I have not been able to get any help as how to establish that. Please help.
The easiest way to do it is by purchasing the following part numbers from Schneider:
2 pieces 990NAD23000 (Modbus Plus Tap)
2 pieces 990NAD21110 (Modbus Plus Drop Cable 2.4 meters)
1 piece 490NAA27101 (Modbus Plus Trunk Cable, 30 meters long, for indoor use)
With this material you should be able to hook together the lower DB9 ports (Modbus Plus Ports). Just make sure that the rotary switches (locatted at the back of Quantum CPUs except the new UNITY High-End ones) are set DIFFERENT one from the other (valid numbers go from 01 to 64).
For peer communication, consult the topics "PEER COP" and "MSTR Function Blocks" on MODSOFT, ProWORX or Concept Programming softwares.
It is pretty straight forward. You have to configure an extension size under the processor configuration. Then go back to the main menu under config and configure the extention. You can configure the PLC port or a NOM. There are global or specific I/O configs<F3>. If you use the NOM then you have to GOTO head and set it. Also, if you used a NOM don't forget to assign a head drop to it in traffic cop.
Are the Quantum Controllers connected to a network? The standard Quantum controller will support both Modbus and the Modbus Plus network connections. If you add a 140NOExxxx Ethernet module tnen they will also support a Ethernet Network.
Since you are specifically asking about a Peer to Peer communication you can do this with either the Modbus Plus or Ethernet Networks. In additon both networks support advanced communication strategies such as Global Data or Publish Subscriber.
If you want to use the Modbus network you will need to use the XXMIT function block to allow the controllers to become the Master of the network. Your application will then be responsible for making sure that both controllers do not attampt to communicate at the same time beacuse you have established a (Master - Slave Network).
To establish peer to peer communications between two quantum plcs you will need to connect the the two plcs together via the modbus plus ports.
As far as configuring in the PLC that will depend on what programming software you are using. If it is Concept you will need to go to the PLC Configuration window, Config Extensions, and enable peer cop. After this select the peer cop setup and setup your read or write to the second plc.
This is pretty straight forward with modbusplus. For details see "modbus plus network planning and installation guide" at Modicon website. you can use MSTR function in each PLC to transfer data to the other. The strategy is that you allocate some registers in each PLC and write some information there from the other. you must also have some communication checks to reset these registers to value 0000 incase there is no communication. we normally use a timer of 10sec. to detect no communication. it depends on the process requirement. The same strategy can be used for more that two PLC's communicating with each other.
