ABB FEPL-02 Ethernet POWERLINK, Руководство пользователя

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94 Communication protocol
The NMT_CS_PREOPERATIONAL states
NMT_CS_PREOPERATIONAL_1 is one of the substates in the
superstate NMT_CS_EPL_MODE. Transition from
NMT_CS_NOT_ACTIVE to NMT_CS_PRE_OPERATIONAL_1 is
triggered by a SoA or SoC frame being received. In this state, the
CN may send a frame only if the MN has authorized it to do so by a
SoA command. There is no PDO communication in this state.
Receiving a SoC frame triggers the transition from
NMT_CS_PREOPERATIONAL_1 to
NMT_CS_PREOPERATIONAL_2. In this state, PReq and PRes
data may be invalid because PDO mappings may differ.
In NMT_CS_EPL_MODE, error recognition (for example, loss of
SoC or PReq) always triggers the transition to
NMT_CS_PREOPERATIONAL_1.
NMT_CS_READY_TO_OPERATE
In this state, the CN signals that it is ready to operate to the MN. It
responds to the PReq query of the MN by sending a PRes frame.
NMT_CS_OPERATIONAL
NMT StartNode command triggers the transition from
NMT_CS_READY_TO_OPERATE to NMT_CS_OPERATIONAL.
This is the normal operating state of the CN.