We got a problem in our ABB AC450 system.

The system consists of [6] AC450 controllers, [15] operating workstation (9000 series based & b2600), [1] IMS workstation (9000 series based). All connected via MB300E network, TCP/IP network and four nodes are connected via fiberoptic conection.

Start: We performed a station restart of the one of the operator stations AS24. While it begins to boot and begins to discover other nodes of the control network MB300 through the RTA board, a message appears in the message line saying "Too many subscriptions".

This message also appears when calling a process display containing process objects of the Advant Controller 1 (AC1). The process objects that don't appear are of the type Analog Input (AI) and Digital Input (DI) of AC1. These process objects on the process object may appear when selected and appear only one time then
disappear again.

We changed this operator station with a new one but in vain. Also we changed the station with a new one and assign a new IP address to it 192.36.66.27 instead of 192.36.66.24, but the problem still exists.

We noticed a system message searching for AS72 [that was an old node with address 192.36.66.72] that we have removed long time ago.

So, we assigned a station as AS72 with address 192.36.66.72 and connected it to the network it worked properly.

Does that mean that there's a malfunctioning in the MB300E when more than 16 stations are inhereting data from system? Is there such limitations on such ABB system?

And what's the solution if I needed to expand my nodes and add some more controllers or stations?

I hope that you help me with a clarification for this problem as I didn't find any definition for this message in ABB manuals.

Thank you guys.

 

You have got too many subscriptions for data on the controller. A controller has got a subscription table built in, in which it stores the receipients of the data. You need to split the workstations up and assign them to different parts of the plant (i.e controllers) so that you don't hit the 16 user subscription limit. If you were to migrate to 800xA this wouldn't be any issue as the Connectivity server would act as one client and these could feed as many operator stations (via Aspect Servers) as you wanted.

You're other issue - the controllers and operator stations remember nodes that have been connected onto the network. There is a way to log onto each of the MB300 nodes and remove the old node from its memory. I have the procedure if you want it.

 

I need the procedure please.

Thank you for helping.

 

Its too much late but i can answer.
Thanks