Echelon Neuron C - Manual (Page 9)

Neuron C Programmer’s Guide ix
Instantiation of Configuration Properties.................................................. 88
Device Property Lists ............................................................................ 89
Network Variable Property Lists ......................................................... 90
Accessing Property Values from a Program............................................... 91
Advanced Configuration Property Features .............................................. 92
Configuration Properties Applying to Arrays...................................... 92
Initialization of Configuration Properties at Instantiation................ 95
Sharing of Configuration Properties .................................................... 96
Configuration Property Sharing Rules ................................................ 97
Type-Inheriting Configuration Properties........................................... 98
Type-Inheriting CPs for NVs of Changeable Type........................ 99
Chapter 5. Using Functional Blocks to Implement a Device Interface.........101
Overview ..................................................................................................... 102
Functional Block Declarations .................................................................. 104
Functional Block Property Lists......................................................... 107
Shared Functional Block Properties .................................................. 108
Scope Rules................................................................................................. 109
Accessing Members and Properties of an FB from a Program................ 110
Accessing Members and Properties of an FB from a Network Tool ....... 112
The Director Function................................................................................ 113
Sharing of Configuration Properties.........................................................115
Chapter 6. How Devices Communicate Using Application Messages...........117
Introduction to Application Messages ......................................................118
Layers of Neuron Software........................................................................ 119
Implicit Messages: Network Variables .................................................... 119
Application Messages................................................................................. 120
Constructing a Message.............................................................................120
The msg_out Object Definition ........................................................... 121
Message Tags ................................................................................ 122
Message Codes .............................................................................. 123
Block Transfers of Data ...................................................................... 124
Sending a Message.....................................................................................125
Receiving a Message ..................................................................................126
The msg_arrives Event ....................................................................... 126
The msg_receive( ) Function ............................................................... 127
Format of an Incoming Message......................................................... 127
Importance of a Default When Clause ............................................... 128
Application Message Examples................................................................. 129
Lamp Program ..................................................................................... 129
Switch Program ................................................................................... 129
Connecting Message Tags................................................................... 130
Explicit Addressing.................................................................................... 130
Sending a Message with the Acknowledged Service ............................... 131
Message Completion Events ............................................................... 131
Processing Completion Events for Messages .............................. 133
Preemption Mode and Messages............................................................... 134
Asynchronous and Direct Event Processing............................................. 135
Using the Request/Response Mechanism................................................. 136
Constructing a Response.....................................................................137
Sending a Response............................................................................. 138
Receiving a Response ..........................................................................138
The resp_arrives Event................................................................. 138