Revision: 0
10
Technical specifications are subject to be changed without notice
8. Control and connection of Network systems, interface protocol
8.1.
Important notes regarding the Network Control Protocol
8.1.1. Binary
Code
The strings shown on the next pages are in binary coded format. Please be aware of the fact that any terminal program you
may use to control a Network unit from a PC must be able to generate hexadecimal characters. ASCII characters will not be
accepted.
8.1.2. Acknowledge
/
Echo
A matrix will reply on a crosspoint set command with an ECHO. In the case where a crosspoint is already set no ECHO will
be sent. If the matrix is part of a MIDI system two types of reply will be sent. Immediately after receiving the crosspoint set
command the ECHO will be sent. The matrix will then wait for the command to pass the MIDI bus system. After receiving
the command from the MIDI bus system the matrix will send the command as an ACKNOWLEDGE.
8.1.3. RS-422
Matrixes
RS-422 Data Routers do not accept distribution of an input signal to several outputs. An input signal can only be routed to
one single output. The Firmware of our RS-422 routers takes care of these limitations. If an input (Source) is already
connected to a particular output (Destination) any connection of this input to another output will disconnect the previous
connection. The router will in this case send the following message for the disconnected output: Output connected to input
128. Input 128 is an internal default for the disconnect status. Please see Network recommendations for use of RS-422 data
routers for further information.
8.1.4. Timeout
The Crosspoint Status Request message has a timeout, which means that you need to wait 1 second in between request
messages.
8.2. Basic
principles
Any message on any level (address) which conforms to the standard arriving at either the MIDI or the RS232 port, will be re-
sent on both MIDI and RS232. The only exceptions are:
a) A matrix which recognizes its address will not re-transmit the message if the crosspoint is already set.
b) A matrix which recognizes its address will not re-transmit the message if the output number or input number
exceeds its size.
c) A unit (matrix or panel) will not re-transmit a message arriving at the MIDI if it was re-transmitted a short while
ago (typically 0.5 sec). This is done by grabbing a message storing it for the timeout period, and comparing it with
new messages. After the timeout period the unit will grab a new message for compare. This is done to remove
unwanted (read: unknown) messages from the MIDI ring.
d) A message arriving at the RS232 will always be re-transmitted unless it is a matrix, and one of the cases a) or b) is
fulfilled.