Toa IC-100 Programmer's Manual page 5

Communicating with the IC-100
Message Tables in this Document
This document describes several types of command messages you can use for controlling and
monitoring IC-100 activity. You will find a separate document section for each command message
type. Each command message section includes a brief explanation, followed by a table detailing
the contents of the fields associated with that message type. The 'Value' column of these tables
displays hexadecimal values with an "H" suffix, and ASCII character values within parenthesis.
Your development tool(s) may not display all of the ASCII characters represented in this
document. True Type and Type 1 fonts reserve characters below 20H for control functions such
as indicating tabs and page breaks, rather than for printing or display.
Many commercial terminal emulator programs install their own font for displaying "non-printing"
control characters. Similarly, 32-bit versions of Windows ship with a special font, aptly named
"Terminal", which displays all of the ASCII characters represented in this document. While
Windows' HyperTerminal and MS Excel support the Windows Terminal font, few other programs
do, as it is neither a True Type nor a Type 1 font.
Message Packaging
All MU-110 serial port messages are packaged using the following format:
<STX><COMMAND><DATA><CHECKSUM><ETX>
The second (
<COMMAND>
Field Name Length
(Bytes)
Stx 1
Command 1
Data 123 max.
Checksum 2
Etx 1
Acknowledgment
The IC-100 transmits a six-byte acknowledgment each time it receives an error-free message
through its serial port.
<STX><COMMAND><RESPONSE><CHECKSUM><ETX>
Field Name Length
(Bytes)
Stx 1
Command 1
Response 1
Checksum 2
Etx 1
IC-100 Programmer's Guide —
) byte of each message identifies its purpose as indicated below.
Value Description
02H ( ) Start of text
23H ( ) Acknowledgment
60H ( ) Remote Dial
70H ( ) Control Station Display Data Stop Request
71H ( ) Control Station Display Data Start Request
72H ( ) Control Station Display Data
Message Dependent
Obtain the CHECKSUM value by finding the sum
of all bytes after STX and adding 30H to each of
the result's two, least-significant, hexadecimal
digits.
03H ( ) End of text
Value Description
02H ( ) Start of text
23H ( ) Acknowledgment
30H ( ) No errors
35H 33H ( ) 23H + 30H = 53H
05H + 30H = 35H ( )
03H + 30H = 33H ( )
03H ( ) End of text
revised September 1999
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