Appendix B – Telnet (Terminal) Commands
116
Instruction Manual – DXLink™ Twisted Pair Transmitters/Receiver
Master Connection Modes
The mode of communication used for connection to the Master is specified via the
SET CONNECTION
Telnet
command (see page 113).
Connection mode setting options are AUTO, TCP URL, UDP URL, or NDP (default) as described:
AUTO
– This mode utilizes TCP communication. It looks for a matching System Number and attempts
to come online with the first Master it sees with that System Number.
TCP URL
– TCP; the Master is specified via URL.
UDP URL
– UDP; the Master is specified via URL.
NDP
– UDP; this mode utilizes the NDP binding process to assign the DXLink Module (the physical
device) to a Master (or Virtual Master) via NetLinx Studio. Once bound, communications are
conducted via UDP.
Note:
In URL modes, the Master can use either an IP address or a DNS name.
Guidelines
UDP mode
is recommended for the following types of installations:
Small-to-medium residential and corporate installations on a single subnet
Segmented control network installations (control network is a separate switching domain and subnet from
other network equipment)
Installations with the total number of NetLinx / ICSNET devices on a single Master exceeding 128
TCP mode
is recommended for installations where (a) the switching domain of the network is subject to
“
bursty
”
traffic
or heavy streaming activity (>20 Mbps consumption by streaming)
and
where (b) the total number of NetLinx / ICSNET
devices on a single Master is less than 128.
TCP vs. UDP
TCP
– Protocol has a built-in retry mechanism.
UDP
– Protocol does not have a built-in retry mechanism, but consumes fewer resources on the Master.
AMX’s UDP implementation of NetLinx employs a retry mechanism to provide the reliability of TCP
with the resource efficiency of UDP.
URL vs. NDP vs. Auto
Determining which connection method to use for Master Connection Mode is essentially a matter of deciding
what information the device should use to identify the correct Master to connect to.
The default mode is NDP; the mode can be changed via the
SET CONNECTION
Telnet command (see page 113).
URL
– The device connects to the Master with the specified URL. The device must be configured with
the URL of a specific Master via the
SET CONNECTION
Telnet command (see page 113).
NDP
– The device connects to the Master it’s been bound to, which is based on the Master’s MAC
address. The binding is configured via NetLinx Studio. Once bound, the device must be unbound using
either NetLinx Studio or the Telnet
NDP UNBIND
command before being re-bound to a different
Master.
Alternatively, NDP devices can be bound/unbound via options on the Master’s Web Configuration
pages (System > Manage NetLinx). For details, refer to the
NetLinx Integrated Controllers -
WebConsole & Programming Guide
(System - Manage NetLinx section).
Auto
– The device connects to the first Master it finds with the specified System Number.
The device must be configured with the desired system number via the
SET CONNECTION
Telnet
command (see page 113).
Use of this method requires that only one Master has any particular system number and is visible to the
subnet. If this is the case, then Auto is the simplest choice. However, with Auto, you are not hard-bound
to a particular Master. Therefore, if at some point in the future, another Master is configured with the
same system number, the result is that the DXLink Module could show up on that other Master.
