Contemporary Research Corporation
9
ICW-STA
RS-232 Control Protocol
Overview
RS-232 control for up to 4000 Tuners, TV Controllers, and Display Controllers is provided through an iC-series
Head-End Network Controller. The ICC-HE Head-End manages iC-Net communication over RF Coax to ICC2-
format controllers as well as ICW-format controllers over twisted-pair Cat3/5 wiring. The ICW-HE Head-End
operates on the twisted-pair network only.
Each unit 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 Zones
in this manual.
In ABC Media Retrieval Systems, 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>,<para> [<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
<para>
Command
parameters (not used by all commands)
[<cmdN>]
Multiple commands can be concatenated, with byte count added to <ncb>