Flow Control Handshaking; Break Handling; Command Responses And Error Messages - evertz 8084 Instruction Manual

SERIAL PROTOCOL
Models 8084/8084AD/8085 Closed Caption Encoder Manual
par Parity
tz Time zone
ovr Override
4.2.3

Flow Control Handshaking

When the encoder's input buffer is nearly full the device sends an XOFF for
each character received. If the Caption software continues to send data
and the input buffer fills completely the caption encoder will show the
message BUFFER OVERFLOW on the front panel display. When the input
buffer has overflowed some data may be lost. When the input buffer is
nearly empty the caption encoder will transmit an XON character.
The 8084 and 8084AD also use hardware flow control to prevent lost data.
The unit will turn off the RS232 RTS signal when the buffer is nearly full,
and will turn RTS on when the input buffer is nearly empty.
4.2.4

Break Handling

A break character can be sent to the caption encoder to cause the content
of the associated input buffer to be discarded. If the break character is
sent to a modem port (Modem D or Modem E), the modem character
buffers will also be discarded. This allows the user to circumvent a backlog
of data input, and regain immediate control of the encoder. The best way
to reset a communications port is to send a break followed by a Control-F –
Control-F command.
4.2.5

Command Responses and Error Messages

When the 8084(AD) accepts any of the Control-A commands it will respond
by sending back an asterisk '*' prompt with the following exceptions:
•
When in real time mode it will respond with a colon ':' prompt.
•
When an article is being defined, it will respond with a '>'.
COMMAND ERROR will be displayed on the front panel if the 8084(AD)
receives a command from a serial control port that it does not
understand. It will also respond by sending back an error code
'E1'.
CMD FMT ERROR will be displayed if the 8084(AD) receives invalid
parameters for a serial command. It will respond by sending
back an error code 'E2'.
Revision 1.6.6
O Odd parity
E even parity
N no parity
0:00 to 23:59 time zone hours and minutes
relative to UTC
O forces override
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