Contemporary Control Systems AI-SRVR Servers to Ethernet User Manual - Manual (Page 14)

TD000200-0MC
14
Then, the Hostname field should be modified if desired.
Next, the BRIDGE fields should be configured.
The Node ID can be any value from 1 through 255 so long as the designated value is
unique within the ARCNET network to which it belongs.
Speed can be set to 156kbs, 312kbs, 625kbs, 1.25Mbs, 2.5Mbs, 7.5Mbs or 10Mbs.
The 7.5Mbs option is not recommended, but it is provided if a special need exists.
* NOTE: The TB5 and CXB transceivers only support 2.5 Mbps. The 485X transceiver
only supports 1.25 Mbps, 2.5 Mbps and 5 Mbps.
By default, the Ext Timeout (extended timeout) value of the AI-SRVR is set to STD (no
extended timeout). If the physical size of the network is so great that extended timeouts
are required, then the Ext Timeout value can be increased to 16X, 8X or 4X. However,
care must be exercised that all nodes within the ARCNET network are set to the same
extended timeout value
— or the network will suffer disruptions.
The COM20022 ARCNET controller within the AI-SRVR is capable of programmable
reconfiguration timeout values. The Recon Timeout setting controls this parameter
which is measured in node counts of 255 (STD), 64, 32 and 16
— allowing operation
with shorter timeouts when the number of nodes permits it. However, care must be
exercised in two respects: If 16Nodes is selected, the network must include a device
whose node ID is 255. And all nodes within the ARCNET network must operate at the
same reconfiguration timeout value
— or the network will suffer disruptions.
If you want the AI-SRVR to receive only those ARCNET packets destined for its unique
node ID, set Receive All to OFF. Otherwise, set it to ON.
Rx Broadcast can be used to enable/disable the reception of Broadcast ARCNET
messages (Destination Node ID 0).
Tx Enable can be used to enable/disable the transmit function of the COM20022
ARCNET controller chip. With the function disabled, the AI-SRVR does not participate
in token passing
— which can be useful to just monitor or receive packets and not
appear as an active node of the network (if Receive All is set to ON).
The number of messages that can be stored in each node's mailbox is limited by the
size of the onboard memory. Each mailbox constitutes a FIFO (first-in-first-out) type of
register. Thus, when a mailbox message limit is exceeded, the first message that was
stored in that mailbox will be lost to make room for the latest message. By default, the
message limit of each mailbox (FIFO Depth) is 5, but this parameter can be set to as
low as 1 or as high as 10. The user can manage memory usage by lowering this value
to accommodate many mailboxes or raising it if only a few mailboxes are used.
The TCP Port number and the UDP Port number are each 5001 by default. Each of
these can be set to a value in the range of 1025
– 65535. However, the only reason to
change either of these values would be if they were in conflict with another application.
Therefore, in almost all situations, these values should be left unchanged
Keepalive Time is the duration between two keepalive transmissions in idle condition.
Keepalive Interval is the duration between two successive keepalive retransmissions, if
acknowledgement to the previous keepalive transmission is not received.