IEC 61131-3 C Tools User Manual

IEC 61131-3 C Tools Structures and Types

UINT16 modbusAddress1;

UINT16 modbusAddress2;

UCHAR controlType;

} dnpBinaryOutput;

 modbusAddress1 is the address of the first Modbus register associated with the point. This field is always used.

 modbusAddress2 is the address of the second Modbus register associated with the point. This field is used only with paired outputs. See the controlType field.

 controlType determines if one or two outputs are associated with this output point. It may be set to PAIRED or NOT_PAIRED.



A paired output uses two Modbus registers for output. The first output is the

Trip output and the second is the Close output. This is used with Control

Relay Output Block objects.



A non-paired output uses one Modbus register for output. This is used with

Binary Output objects.

DNP_CONNECTION_EVENT Type

This enumerated type lists DNP events. typedef enum dnpConnectionEventType

{

DNP_CONNECTED=0,

DNP_DISCONNECTED,

DNP_CONNECTION_REQUIRED,

DNP_MESSAGE_COMPLETE,

DNP_MESSAGE_TIMEOUT

} DNP_CONNECTION_EVENT;



The DNP_CONNECTED event indicates that the handler has connected to the master station. The application sends this event to DNP. When DNP receives this event it will send unsolicited messages.



The DNP_DISCONNECTED event indicates that the handler has disconnected from the master station. The application sends this event to

DNP. When DNP receives this event it will request a new connection before sending unsolicited messages.



The DNP_CONNECTION_REQUIRED event indicates that DNP wishes to connect to the master station. DNP sends this event to the application. The application should process this event by making a connection.



The DNP_MESSAGE_COMPLETE event indicates that DNP has received confirmation of unsolicited messages from the master station. DNP sends this event to the application. The application should process this event by disconnecting. In many applications a short delay before disconnecting is useful as it allows the master station to send commands to the slave after the unsolicited reporting is complete.

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