M580 HSBY

[Anonymous user]

Hello All, 

I have Modicon M580 HSBY with 2 NOC Modules in Rack A and Rack B. These 2 NOC Modules are for Redundant Communication with Yokogawa DCS. Whenever 1st NOC is failed, it takes 2 seconds delay to switchover from NOC 1 to NOC 2. These delay is causing communication break / halt. i want to to reduce this 2 seconds delay.

thank you 

Israa 

[RoozeeR]

Hello Israa,

Can you explain a bit more, who is taking the initiative for communication, Yokogawa system or M580? In other words, what is programmed in the M580 to start communication with Yokogawa DCS?

[BevanWeiss]

As noted, you might need to supply a little bit more information:

• What model of NOC is in each rack?
• What protocol is in use for the communication?
• Could you provide a block diagram of the connection architecture (including each ethernet segment if there are a number of such)?
• What mechanism are you using to 'fail' the NOC?

Certain protocols (i.e. Ethernet/IP CIP) have inbuilt support for redundant links, but many others do not (i.e. ModbusTCP) and hence the link redundancy must be handled well up in the stack (typically beyond the session layer in the OSI model).  This means that such redundancy is 'left up to the reader' in regards to how it is implemented, and some of the additional limitations of it.

If using ModbusTCP, you could send the same messages on both 'channels', or perhaps even all four channels if you will architect it this way.. (i.e. NOC1 -> Yoko1, NOC1 -> Yoko2, NOC2 -> Yoko1, NOC2 -> Yoko2)... in this manner there should be very minimal disruption if any single channel failed, however data synchronisation issues may be somewhat problematic (again... a task left up to the reader).

[jaysonlkh]

Hi Israa,

I believe you are referring to the communication with Yokogawa ALE111 module, you need to inform Yokogawa to put some buffer time during detect primary NOC is down and required to switchover. Hope this will help to answer your concern.