5.2 Reques t commands
Request commands can be sent from the
RCS
to the
RCM
or vice versa. The answer of a request com-
mand does not include the status information.
Command "R": Calling for Address
Description: Request for an address.
A
RCS
that is not provided with an address will send requests for an address at regular
intervals.
This message uses the command
R
. It will be received by the
RCM
and signals the need
for a new addressing procedure.
Example:
An
RCS
of class
m
asks for an address:
Message
<STX> <TYPE> <ADDRH> <ADDRL>
<Body>
<STATH>
<STATL
<CHKH>
<CHKL> <ETX>
m
0
0
R
b
f
Command "A": Addressing Procedure
Description: Each member of the remote control chain must have a non-ambiguous address so that
functions can be specifically triggered in the individual devices. The addresses are as-
signed by an initial addressing message. Since all devices of a certain class have to be
given a non-ambiguous address, and since at the beginning the
RCM
does not know how
many devices exist, the command uses as
<ADDRH> <ADDRL>
the "00".
Message
<STX> <TYPE> <ADDRH> <ADDRL>
<Body>
<STATH>
<STATL
<CHKH>
<CHKL> <ETX>
m
0
0
A
0
e
The addressing message uses the command
A
. In the above example all
RCS
of class
m
are addressed.
The first
RCS
increases the number. The resulting number is his individual address. Afterwards he cal-
culates the new checksum and passes this modified message to the next device. Each device conse-
quently increases the numbers before passing the message again. The last
RCS
passes the message back
to the
RCM
. (The maximum number of
RCS
in a class is 98). The addressing procedure must be carried
out separately for all types of
RCS
in the remote control ring.
Example: Let's consider a class of H
ERMES
DXD consisting of 3 devices. They all have to get their non-
ambiguous address by the initial addressing message. The message passed by the last
RCS
back to the
RCM
informs the
RCM
about the number of devices of this class.
RCM
RCS1
RCS2
RCS3
passes
m00A0e
receives
m00A0e
passes
m01A0f
receives
m01A0f
passes
m02A10
receives
m02A10
passes
m03A11
receives
m03A11
Answer
<STX> <TYPE> <ADDRH> <ADDRL>
<Body>
<STATH>
<STATL
<CHKH>
<CHKL> <ETX>
m
0
3
A
1
1
