Specifications

STB NIP 2311 Services
EIO0000000051 6/2010 155
Understanding Processing Control
The STB NIP 2311 module can be configured to recognize up to three controllers as
master controllers. The module should continuously maintain an open connection
with at least one master controller.
If the STB NIP 2311 module loses all connections with master controllers:
z It waits a prescribed time (Holdup Time) for a master controller to establish a new
connection with the STB NIP 2311 module.
z If no new connection is established before the timeout period expires, the
STB NIP 2311 module sets island outputs to their fallback states.
Understanding Connection Priority
The STB NIP 2311 module can maintain up to 16 simultaneous Modbus TCP
connections, with one or more Ethernet devices.
Any controller on the Ethernet network can connect to the STB NIP 2311 module
and write to:
z the Advantys island’s output data process image
z the Advantys island’s configuration settings
Ordinarily, the STB NIP 2311 module grants connection requests on a first-
come/first-serve basis. Once granted, a connection remains open until the device
ceases to communicate with the STB NIP 2311.
When a master controller requests a connection, its request is given priority over
other non-master controllers, even if the non-master controller is already connected
to the STB NIP 2311.
When the STB NIP 2311 module reaches its maximum number of 16 simultaneous
connections, it must close an existing connection before it can open a new one. The
NIM closes existing connections based on the time of a connection’s most recent
transaction; it closes the connection whose most recent transaction is the oldest.
However, all connections between the STB NIP 2311 and a master controller are
preserved. The controller does not close a connection with a master in order to open
a new connection.