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6.1 Structu re of message
The messages consists out of a
parts are interpreted the same by all types of devices. The
mands for a certain type of
A message has the following structure:
<STX> <TYPE> <ADDRH> <ADDRL> <Body> <CHKH> <CHKL> <ETX>
These are the elements of a message in detail:
STX
<TYPE>
<ADDRH><ADDRL>
<Body>
<CHKH><CHKL>
ETX
6.2 Proces sing a command in broadcast mode
As soon as an
recognizes that the command is sent in broadcast mode (e.g. in case of H
RCS
DXD, the second character is an upper case
following
. This ensures that all
RCS
time", thus being able to execute "simultaneously" the required action.
For broadcast commands, there is no acknowledge. However, the broadcast
message will loop back completed and unmodified to the RCM and may be
interpreted as acknowledge.
-independent and a
RCS
: the message body.
RCM
The control character STX (Ctrl-B) is the beginning of a
message. All previously received characters are ignored and
are not sent on. (Ctrl-B is displayed as
applications.)
1 byte ASCII
upper case class code to specify broadcast addressing.
2 bytes ASCII decimal
in broadcast addressing it is always 00
type-dependent part of the message, e. g. a command
2 bytes ASCII decimal
is the sum over all fields from <TYPE> to <Body>. The
checksum is evaluated by the recipient.
The control character ETX (Ctrl-C)is the end of a message.
(Ctrl-C is displayed as
), it immediately starts passing the entire message to the
M
of the Remote Control ring receive the command "at the same
RCS
-dependent layer. The
RCS
-dependent parts contain specific com-
RCS
in most terminal applications.)
-independent
RCS
in most terminal
Table 6-1
ERMES
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