PM866 Redundant Connections
Purpose of using BC810 :
"The primary function of BC810 is to divide the CEX-Bus into two physically separate segments for increased system availability, a faulty CEX-Bus unit on one segment will not affect the processor unit or the other CEX-Bus segment. It is also important to note that when using the BC810 together with redundant CEX-Bus units these units shall be mounted on different BC810 CEX-Bus segments." When using BC810 with Redundant Configuration of PM866, there is need to use only RCU Link Cable (TK851) for connection between Red Controllers as well as between Red BC810. Refer pg.98 of same manual, screenshot attached, which points notification about non requirement of TK850 Cable. However, in page 400, it should have been mentioned as "when Red AC800M Controllers configuration is used without BC810" or as an exception stating " Except case where BC810 is used in Red Configuration along with red Controllers". Hope it clears your doubt.
Here two questions:
1.Red.PM866 without BC810: Then offcourse you have to use the TK850 CEX-bus extension cable between two segments"UPPER" & LOWER controllers.
Here you can extend the CEX bus from 1 to 12 always count starts from upper controller like Upper controller(0)cexmodule(1)cexmodule(2)-TK850 cable-cexmodule(3)-cexmodule(4)-Lower controller so like this you can extend upto 12 only but here you have to select the CEX positions while selecting redundancy.
2.1.Red.PM866 with BC810:If you are using BC810 then don't use the CEX-bus extension cable(TK850) to connect two CEX-bus segments(UPPER & LOWER).
So you can put max of 6 CEx modules/segment like 1 to 6 in upper segments & 7 to12 in Lower segments.
So for redundant CEX modules will take the count as 1(7),2(8) etc.
The primary function of BC810 is to divide the CEX-BUS segments into physically separate sgements as UPPER & LOWER segments to enusure increased availability.
So by using BC810, we can remove the faulty PM866 with baseplate in online without disturbing the process or it doesn't affect the other running PM866 with their CEX bus segments.
So by using BC810 we can achieve the cross communication(more availability of controller & CEX bus devices).
Cross communication means:
1.If Upper controller(PM866) & Lower CEX modules fails, either by switched off controller & by removing the CEX modules ensure only HOT swap modules you can remove still your process remains stable through Lower controller & upper CEX bus devices this is achieved through BC810 which powers the CEX modules which were mounted adjascent to this module.
2. 1.If Lower controller(PM866) & upper CEX modules fails, either by switched off controller & by removing the CEX modules ensure only HOT swap modules you can remove still your process remains stable through upper controller & lower CEX bus devices this is achieved through BC810 which powers the CEX modules which were mounted adjascent to this module.
So always prefer to use ths redundancy with BC810 instead going for without BC810.
So for your doubt Pm866 with BC810 running from last 1year regarding without TK850 cable?
No problem will occur its the configuration you can achieve more availability of the system.
I would also like to ask 1 more question in this regard of Red Controller configuration with Red BC810.
Red BC810 has possibility of taking Power from Controller (using Modulebus) or Power can be externally connected to BC810 Terminals.
For Sourcing External Power to BC810, There are 2 possibilities of sourcing power to BC810 :
1. Either shared with same power source as Controller base plate or
2. Can be separate power source.
In either case, if there is problem related to Controller on Primary Side and it needs to be replaced, is it recommended to remove the Controller along with baseplate with Power still available on BC810 ?
Or first Upper CPU and BC810 power must be switched Off and then Controller can be removed.
To rephrase in other words, "Is it recommeded to replace CEX Bus Modules e.g. CI's or Faulty Controller, with respective BC810 still powered On ?"