Contemporary
Research
17
ICC2-ATSC HDTV Tuner/Controller
IC-Net Control Protocol
Overview
RS-232 control for up to 4000 TV Controllers is provided through an iC-series Head-End Network
Controller. The ICE-HE Ethernet Head End and ICC-HE Head End manage iC-Net communication
over RF Coax to ICC1 (1-way) and ICC2 (2-Way) TV Controllers.
Each TV Controller is assigned a unique device number from 1 to 4000 to which control
commands are addressed. The devices are organized into 16 zones of 255 devices. All the devices
in each zone will respond to a single “virtual device number” — one device number that
represents all devices in each zone. There is also a global device number, 4095, that will
command all devices in the system. This feature dramatically speeds up system operation and
programming, because one command can affect an entire group of devices—or all. To take
advantages of this feature, review the section iC-Net SmartZones in this manual.
In ABC-Net, we reserve the first group of devices, 1-255, for components operating on a
connected control system. Zones 1-16 are used for CR TV Controllers, Video Display Controllers
and Tuners. As it’s unlikely any system will use all 4000 devices, this may be a good device
standard for your system as well.
The Remote RS-232 port on the Head-End Network Controller can communicate from 1200 to
38.4K baud. The factory default setting is 19.2K baud, 8 data bits, No parity, and 1 stop bit.
Command String Structure
Characters in command strings are expressed in a combination of hex and ASCII characters. For
clarity, the following protocol examples use the following conventions:
•
Single-byte hex numbers are preceded by the ‘$’ symbol
•
ASCII characters or strings are enclosed in single quotes
•
Numbers not marked as hex or ASCII are a single decimal byte
•
Parameters shown in < > brackets are single byte
•
A series of multiple commands or parameters are set apart by [ ] brackets
•
Commas separate the bytes, but are not part of the protocol
•
Double quotes enclose the command string, but are not part of the protocol
Command format:
“$A5,<dh>,<dl>,<ncb>,<cmd1>,<parameter> [<cmdN>]"
$A5
Starts the command
<dh>
The zone or high order byte of the device*
<dl>
The unit or low order byte of the device (0 for global zone)
<ncb>
The number of command bytes to follow
<cmd1>
The first command byte
<parameter> Command parameters (not used by all commands)
[<cmdN>]
Multiple commands can be concatenated, with byte count added to <ncb>
*
iC-Net devices are arranged with a zone mindset. For example, a command sent to Device 256, which
triggers all the units in Zone 1, would be expressed as $A5, 1, 0 (first zone, device zero). A command sent
to 257 would be $A5, 1, 1 (first zone, device 1 in the zone). See iC-Net SmartZones toward the end of this
manual.
