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5.7 Error m essages
Three different kind of errors might occur:
The body is an invalid command
The checksum is not correct
The device cannot be addressed (it might be switched off…)
The information sent back to the RCM about these errors does not include the status register
Error Protocol "EP"
Description: Via this answer the
RCM
is told by the
RCS
of class
m
that the body has been an invalid
command.
Example:
The
RCM
has sent a command x to the
RCS
.
Message
<STX> <TYPE> <ADDRH> <ADDRL>
<Body>
<STATH>
<STATL
<CHKH>
<CHKL> <ETX>
m
0
2
y
4
8
Since the command y does not exist for an
RCS
of class m, the
RCS
sends this message
back to the
RCM
, adds the extension
EP
(Error Protocol), and calculates the new check-
sum.
Answer
<STX> <TYPE> <ADDRH> <ADDRL>
<Body>
<chksm>
<ERR>
<CHKH>
<CHKL> <ETX>
m
0
2
y
48
EP
4
9
Error Checksum "EC"
Description: Via this answer the
RCM
is told by the
RCS
of class
m
that the checksum has not beeen
correct.
Example:
The
RCM
has sent the following command:
Message
<STX> <TYPE> <ADDRH> <ADDRL>
<Body>
<STATH>
<STATL
<CHKH>
<CHKL> <ETX>
m
0
2
t
3
0
The correct checksum of the above command is 43. The
RCS
detects an checksum error,
sends the command back to the
RCM
and adds the extension
EC
(Error Checksum)
Answer
<STX> <TYPE> <ADDRH> <ADDRL>
<Body>
<chksm>
<ERR>
<CHKH>
<CHKL> <ETX>
m
0
2
t
30
EC
2
e
Содержание Hermes DXD
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Страница 13: ...2 Summary This chapter gives an overview of the HERMES DXD ...
Страница 50: ...7 Technical Data ...