THOMSON DD10, Installation Manual

Page: 118 / 179

7. Description of the Interface Diamond digital
109
The mnemonic codes are transmitted in the following binary form:
10010101 aaaaaaaa 0ccccccc 0ccccccc 0ccccccc 0ccccccc
”a” corresponds to the XBAR output number entered during the installation in the
IDENT INPUT Menu and ”c” correspond to the ASCII coded characters of the
mnemonic codes to be transmitted.
During the start-up phase the switcher sends a INIT REQUEST (hex BE). This
informs the host that the switcher had been switched off and may have lost data or
that the data may not be current. The host must respond by sending all mnemonic
codes again.
During the normal operation the switcher sends “I AM DIAMOND” (hex BF) at regu-
lar intervals (every 3 seconds). If the host is switched on, it should answer by send-
ing all mnemonic codes until the switcher sends this message for the first time. The
subsequent regularly arriving messages may be ignored. They may be used in the
host to check that the connection is still alive.