Acyclic Read/Write Request Sequence - GE AF-650 GP PROFINET Operating Instructions Manual

PROFINET Acyclic Communicat... PROFINET Operating Instruction

7.1.4 Acyclic Read/Write Request Sequence

A Read or Write service on a drive parameter will take place as illustrated in Illustration 7.2.
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Illustration 7.2 Acyclic Read/Write Request Sequence
A Read or Write on a drive parameter must be initiated by an acyclic write service on slot 0, index 47. If this Write request is valid,
a positive write response without data is returned from the drive immediately. If not, a negative write response is returned from
the drive.
The drive will now interpret the "Profidrive parameter channel" part of the Data Unit, and start to perform this command internal
in the drive.
As the next step, the master will send a Read request. If the drive is still busy performing the internal parameter request, a
negative response without data is returned from the drive. This request will be repeated by the master, until the drive has the
response data ready for the drive parameter request.
The following example shows the details of the telegrams needed for the Read/Write service.
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