Operating Instructions – MOVITRAC® B
107
5
Communication and unit profile
Startup
Bit 6
is the handshake bit. It has a different meaning depending on the bus system:
• With SBus 1 (CAN) and set handshake bit (= 1), the response telegram is sent after
the synchronization telegram.
• With RS485 and fieldbus, the handshake bit serves as acknowledgement bit be-
tween client and server when using the cyclic transmission method. As the parame-
ter channel is transmitted cyclically in this variant, probably with the process data, the
implementation of the service in the inverter must be triggered by edge control using
handshake bit 6. For this purpose, the value of this bit is toggled for each new service
to be executed. The inverter uses the handshake bit to signal whether the service
has been executed or not. The service has been executed as soon as the handshake
bit received in the controller is identical with the transmitted handshake bit.
Status bit 7
indicates whether the service was executed properly or whether errors oc-
curred.
Response
The response to a parameterization request is structured as follows:
• The management byte of the response telegram is structured like that in the request
telegram.
• The status bit indicates whether the service was executed successfully:
– If the status bit is set to "0", bytes 4 to 7 of the response telegram will contain the
requested data.
– If the status bit is set to "1", an error code is indicated in the data area (bytes 4 to
7), see chapter "Incorrect service execution" (page 109).
Description of the
parameter services
Bits 0 - 3 of the management byte are used to define the individual parameter services.
MOVITRAC
®
B supports the following parameter services:
No service
This coding indicates that there is no parameter service.
Read parameter
This parameter service is used to read a drive parameter.
Write parameter
This parameter service is used for non-volatile writing of a drive parameter. The written
parameter value is stored non-volatile (e.g. in EEPROM). This service should not be
used for cyclic write accesses because the memory modules allow for only a limited
number of write cycles.
Write parameter
volatile
This parameter service is used to write a drive parameter volatile, if the parameter per-
mits this. The written parameter value is only stored in the non-permanent RAM of the
inverter, which means it is lost when the inverter is switched off. The value written last
with write parameter is still available when the inverter is switched back on.
Read minimum
This service can be used to determine the smallest value (minimum) that can be set for
a drive parameter. The coding corresponds to the parameter value.
Read maximum
This service can be used to determine the largest drive parameter value (maximum) that
can be set. The coding corresponds to the parameter value.
Read default
This service can be used to determine the factory setting (default) of a drive parameter.
The coding corresponds to the parameter value.
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Summary of Contents for Movitrac B
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