FINS command; broadcast to all nodes

[Neo 0]

Hi all I am working on a project using FINS commands over ethernet to communicate between a CJ1G-45H PLC and two TJ1-MC16 Trajexia motion controllers. I am able to send data to each Trajexia individually but would like to braodcast to both nodes to speed up the process. In the FINS command reference manual it states that if the node number is set to "255 decimal" the FINS command will broadcast to all nodes on the network. However, this is not the case for me, am I missing something here? Any help would be great. Laters Neo

[Harald_Brueck 0]

Dear Neo, somehow the information is not wrong, but I think you cannot use it for IP-messages on Ethernet. If you might have a PLC with Ethernet and a Controller-Link-Network, you can send from a PLC on the Ethernet to the Gateway-PLC a FINS-message, where you give the network number of CLK as destination network and node number 255, then the message will be broadcasted on all nodes on CLK. That is why you can put 255 as node number. On Ethernet you have the IP-protocol underneeth ot FINS, and there you are not able to put a broadcast address from the PLC-program, I think. Annother solution: Just activate both CMND (FINS-Delivery)-instructions for both Trajexias at once. Just give them different logical communication ports. The ETN21 will be able to handle it. It will wait for the first answer on one logical communication port (A202.x1) and it will wait for the other answer on the other logical communication port (A202.x2) The commands will not exactly arrive at the same time at the both Trajexias, but the time difference will be very smal. In a test I tried to send several FINS messages to a single Trajexia without waiting for the answer, this worked, but after some time the Trajexia had a bit trouble. With two Trajexia it should work. Harald

[Neo 0]

Thanks Harald I was wondering if using different logical ports might work. I have figured out a sequence of reads and writes to communicate to each Trajexia one at a time. Obviously this is not the best way so I might try the multiple logical port method. Kind Regards Neo

[JYG 13]

I am using a CJ2M CPU31 with EtherNet/IP and sending broadcast (node 255) and it works perfectly. You must be aware that the broadcast use the port you have set in the configuration (by default 9600), so the client must listen on that port. http://www.criq.qc.ca Edited 7 Oct 2014 by JYG