
The table below gives an example of a "long message" read command.
Figure 27: Example of a "long message" read command
7.5.3
Error handling in the Parameters Channel
Errors in a "short message" are handled differently than for a "long message".
If a "short message" is transmitted to the motor feedback system with an error, the pro‐
tocol sends the message again automatically until an acknowledgment of correct trans‐
mission is received. This is not explicitly indicated to the frequency inverter. The
FRES
flag remains deleted until correct receipt of the answer to the "short message".
If the DSL Master receives no acknowledgment of the transmission of a "short mes‐
sage", the protocol automatically begins cyclic repetition of the transmission.
There is no limit to the number of repetitions and the user must decide when to issue a
message reset.
If the DSL Master receives no acknowledgment of the successful reception of a "long
message" from the DSL slave, the protocol automatically begins a cyclic repetition of
the transmission until such an acknowledgment is received. This has no internal time‐
out.
If a "long message" is transmitted correctly to the motor feedback system but the
answer received from the DSL slave is not valid, the
ANS
flag in the
EVENT_L
register
will be set. In that case, "the long message" will not be repeated. The user needs to per‐
form the same "long message" action once again.
7
CENTRAL FUNCTIONS
72
T E C H N I C A L I N F O R M A T I O N | HIPERFACE DSL
®
8017595/ZTW6/2018-01-15 | SICK
Subject to change without notice