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ATSC-mini HDTV Tuner Product Manual 022021
RS-232/Telnet/UDP Control Protocol
The ATSC-mini full duplex RS-232/Telnet protocol enables a system programmer to control all tuner functions, configure the tuner, and
monitor tuner status. All commands are sent as ASCII strings. No delays between characters or commands are required, as data is interrupt
driven and buffered.
Communications parameters are 1200 to 230,400 baud, 8 data bits, no parity, and 1 stop bit. Factory default is 9600 baud. All settings are
saved to NVRAM in the ATSC-mini tuner. The RS-232 port will accept non-standard control such as voltage that swings from 0 to +5 VDC,
commonly found when IR ports are used to send RS-232 commands.
The same commands can be sent over IP Telnet (up to two sessions) and via UDP to the tuner’s IP address to port 31931 (fixed)
. UDP
responses are disabled by default. Responses will be sent to port 31932 at the directed
broadcast IP address of the tuner’s subnet.
UDP
responses may be enabled in the on-screen text menu, web page Network Settings menu, or RS-232 command. See our Support Blog
Testing 232-ATSC Series UDP Control at
https://contemporaryresearch.com/testing-232-atsc-udp-control/
to learn more about UDP control.
General Protocol Specifications
Characters in command strings to the ATSC-mini are common ASCII keyboard characters. Command strings sent to the ATSC-mini begin with
the ASCII > (greater than symbol) as an ‘Attention’ character and end with carriage return
- ASCII CR, Hex $0D, or keyboard Enter - as an
‘End
-of-
command’ character.
For commands that require a parameter value, the = (equals symbol) shown in the examples is optional.
Responses from the ATSC-mini
begin with the ASCII < (less than symbol) as an ‘Attention’ character and end with a ca
rriage return followed
by a line feed -
ASCII LF or Hex $0A as an ‘End
-of-
command’ character.
A carriage return is required at the end of each command and is assumed in all examples.
Command String Structure
[Attention] [Command] (Parameters) [Return]
Attention
Single character (>) starts the string
Command
A two-character command
Parameters
Added attributes to some commands
Return
A carriage return ends the command string. ASCII CR, Hex $0D, or keyboard ‘Enter’ may be used in programming. For
simplicity, the programming examples in the manual will not show the ‘CR’.
Command and Status Response
Commands can be sent back-to-back at any time without any delay. To allow for rapid, multiple commands, status responses are
intentionally delayed by about 125 mS, sending the most recent status in response to control commands or user actions.
String Example
The example below is a command for a channel change to 6-2 followed by the response string.
>TC=6-2
<1TU006Uxx1002x0
The status of a setting may be queried by omitting the = (equals symbol) and the parameter value. The following command queries the 63
step volume level.
>VL
<VL=62
