The resource description in
contains an explanation of the purpose for
which offset addressing is used. Using offset addressing, an additional "long message"
parameter can be transmitted to the motor feedback system as well as the address
(
ADD
) and the message data (
DATA
).
If the
O/N
characteristic is set to "1", then the
OFF ADD
characteristic must contain the
value for the offset address characteristic.
The same
O/N
bit in the
PC_ADD_H
register can be read after receipt of the "long mes‐
sage" answer to determine the
ERR
error characteristic.
Table 37: ERR value for the "long message"
ERR value
Error during resource access
0
No error
1
An error was identified
If the motor feedback system discovers an error during a resource access, the
ERR
bit
is set and the
LEN
characteristic is set to 2 bytes (01b).
In this case the
PC_BUFFER0
and
PC_BUFFFER 1
DATA
registers will contain an error
code as detailed in
. This error code enables precise error handling for
"long messages".
D/I
determines whether direct or indirect addressing is used for a "long message".
Table 38: D/I value for the "long message"
D/I value
"Long message" addressing
0
Direct addressing
1
Indirect addressing
The resource description in
contains an explanation of the purpose for
which direct or indirect addressing is used.
The
LEN
characteristic determines the data length of the "long message".
describes the use of this characteristic.
LEN
must correspond to the permitted values applicable to the resource addressed
(see
). If these values are not observed, the "long message" in the motor
feedback system will be ended and a corresponding error message indicated.
The
ADD
characteristic determines the target resource of the "long message". The
ADD
value corresponds to the RID resource index.
Table 39: ADD value for the "long message"
ADD value
Resource index (RID)
000h to 3FFh
000h to 3FFh
Access to resources not installed in the motor feedback system is ended with a corre‐
sponding error message.
The
OFF ADD
"long message" characteristic contains the offset address, provided off‐
set addressing is used (see above under the
O/N
characteristic). The resource descrip‐
contains an explanation of the permitted scope and purpose of each
individual resource.
Table 40: OFF ADD value for the "long message"
OFF ADD value
Register used
0000h to 7FFFh
PCR_ADD_H/PCR_ADD_L
Access to a resource with an invalid
OFF ADD
value, or one that is too high, will cause
the "long message" in the motor feedback system to be ended and a corres- ponding
error message will be indicated.
CENTRAL FUNCTIONS
7
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T E C H N I C A L I N F O R M A T I O N | HIPERFACE DSL
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