Grass Valley TTN-BES-0808CP/75 - Manual (Page 19)

BES-0808CP/75 Rev. 2
11
7 Control and connection of Triton systems, interface protocol
7.1 Important notes regarding the Triton Control Protocol
7.1.1 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 Triton unit from a PC must be able to generate hexadecimal
characters. ASCII characters will not be accepted.
7.1.2 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 an NCB 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 NCB system. After receiving the command from the NCB system the matrix
will send the command as an ACKNOWLEDGE.
7.1.3 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 would 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 Triton recommendations for use of RS-422 data routers for further
information.
7.1.4 Timeout
The Crosspoint Status Request message has a timeout, which means that you need to wait 1 second in
between request messages.
7.2 Basic principles
Any message on any level (address) that conforms to the standard arriving at either the NCB or the
RS232 port will be re-sent on both NCB and RS232. The only exceptions are:
a) A matrix that recognizes its address will not re-transmit the message if the crosspoint is already
set.
b) A matrix that 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 NCB 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 NCB
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.
7.2.1 Example: A single unit with no NCB connected
Messages sent to the RS232 of a single unit will be returned once no matter what address or input/output
number the message has, unless it is a matrix which recognizes one of the conditions a) or b) above.