Escient MP-150 Radio User Manual


 
EXTERNAL CONTROL PROTOCOL WD031-1-3
4/18/2005
6325 Digital Way Indianapolis, IN 46278 317.616.6789 phone 317.616.6790 fax www.escient.com
External Control Protocol Specification
Commands and Responses Overview
Version 03.11.13.02.00
The external control protocol is standard ASCII based. ESCX is the four-letter preamble that is
used for all commands. This preamble must be uppercase. The commands provided in this
protocol allow an external control system to navigate the Escient products, get library
information to build custom user interfaces, perform transport controls, and receive unsolicited
feedback on system status.
All external control commands are made up of the preamble (ESCX), command group
(01,02,10,20,50,70), sub command (specific task), specific data (# of data items, and a size of
data packet then the actual data packet repeated for the # of data items), and a carriage return
end marker.
External Control Command Structure
DESCRIPTION
PREAMBLE
COMMAND
GROUP
SUB COMMAND
# DATA ITEMS
DATA ITEM #1
SIZE
DATA #1
DATA ITEM #2
SIZE
DATA #2
END MARKER
Bytes 4 2 2 3 4 5 4 3 1
Example ESCX 01 08 002 0005 Hello 0003 Bye
Carriage
Return
The external control commands are broken down into the following Command Groups:
01 – Command Responses
02 – Unsolicited Events
10 – Remote Button / Keyboard Commands
20 – Database Commands
50 – Status Commands
70 – Control Commands
All commands will cause one of the following response numbers to be issued. Some
commands, such as database commands will also send back additional responses that contain
more detailed information.
Command Responses
COMMAND
GROUP
RESPONSE NUMBER RESPONSE DESCRIPTION
01 01 OK
01 02 Bad Command Structure
01 03 Empty Library or Bad Range