Documentation

MbusDataTableInterfacewriteHoldingRegistersTable Method

Override this method to implement a Data Provider function to write Holding Registers.

Namespace:  FieldTalk.Modbus.Slave
Assembly:  FieldTalk.Modbus.Slave (in FieldTalk.Modbus.Slave.dll) Version: 2.11.0-eval+eb1ecbe71c969eff5d7c05d58da16dade0474678
Syntax
Copy
protected virtual bool writeHoldingRegistersTable(
	int startRef,
	short[] regArr
)

Parameters

startRef
Type: SystemInt32
Start register (Range: 1 - 65536)
regArr
Type: SystemInt16
Buffer which contains the received data (Length: 0 - 125)

Return Value

Type: Boolean
true indicates a successful access. The Server Engine will send a positive reply to the master.

false indicates that access has been denied or is out of range. The Server Engine will reply to the master with an exception reply message

Remarks
When a slave receives a write request for the 4:00000 data table it calls this method to pass the data to the application.

Required: Yes

Default Implementation: Returns false which indicates to Server Engine that this address range is unsupported.

Examples
A simple implementation which holds the application data in an array of Int16 called localRegisters could be:
Copy
protected override int writeHoldingRegistersTable(Int32 startRef, Int16[] regArr)
{
    // Adjust Modbus reference counting from 1-based to 0-based
    startRef--;
    // Validate range
    if (startRef + regArr.Length > localRegisters.Length)
        return false;
    // Copy registers from Modbus to local data block
    for (int i = 0; i < regArr.Length; i++)
        localRegisters[startRef + i] = regArr[i];
    return true;
}
See Also