HD490 Smart Encoder
23 Copyright © 2000-2012 EEG Enterprises, Inc.
All Rights Reserved.
333 Serial Output In 333 serial output, the Encoder sends its 708 caption output to a serial
output queue to wait for transport to an ATSC encoder supporting the
SMPTE 333M protocol. 333 is a “pull” protocol; a properly configured
ATSC encoder will send synchronization requests (SYNs) to the caption
encoder, which then sends data chunks from the output queue to serial
port P1. For complete information about the protocol, refer to the
SMPTE 333M specification.
To set the Encoder for 333 serial output, simply connect P1 to the
captioning port of a SMPTE 333M ATSC encoder. When the Encoder
begins receiving SYNs, it will automatically enter the 333 output mode.
P1 is default-configured on startup for the proper communications
settings to listen for 333 (38400 Baud, 8 data bits, no parity, and one
stop bit). To set the Encoder for 333 output manually, and set P1 to the
proper listening settings, use <CTRL+A>f 333 <ENTER>.
GA Serial Output In GA serial output, the Encoder sends its 708 caption output to a serial
output queue for transport to an ATSC encoder supporting Grand
Alliance (GA) protocol. Grand Alliance is a “push” protocol; the
caption encoder sends data out through P1 as it becomes available, and
the ATSC encoder synchronizes the data upon reception. The Grand
Alliance transport protocol in use by EEG equipment is described on
page 46 of this manual.
Since the caption encoder initiates data transfer with a Grand Alliance
ATSC encoder, GA output must be begun manually. The command to
set the Encoder for GA output is <CTRL+A>f ga <ENTER>. This
command will begin the GA serial output and set P1 for the proper
communications rate (19200 Baud, 8 data bits, no parity, and one stop
bit).
Note that, each time the HD490 is power cycled, the default startup
behavior is to return to the HD VANC Insertion mode. If a SMPTE
333M ATSC encoder is connected to P1, 333 serial output will begin as
soon as SYNs are received. If GA serial output is the desired mode on
each startup, the GA output command can be stored in Startup Settings
To Next Page
Loading...
