FC_ComIecWrite - General Information

Overview

Type:	Function
Available as of:	SystemInterface_1.32.6.0
Versions:	Current version

Task

Write character to the logical device.

Description

This function writes characters to the logical device i_stComIecId. It writes i_diSize characters. When calling, transfer the address of a variable to i_diBuffer. The characters to be written are taken from this variable. The function transfers the data to the serial driver and returns. The driver performs the write operation autonomously.

NOTE: Note for "RS 485 2-wire" that the hardware has to switch (TriState) between transmitting and receiving. Therefore, a waiting period of at least 5 ms is necessary between sending ( FC_ComIecWrite()) and receiving ( FC_ComIecRead()).

Interface

Input	Data type	Description
i_stComIecId	ST_LogicalAddress	Device selection
i_diBuffer	DINT	Buffer address
i_diSize	DINT	Number of characters that have to be written

Return Value

Data type	Description
DINT	0...: Number of bytes written -1: i_stComIecId invalid -2: other error detected. Contact your Schneider Electric representative.

Examples

Task

Write a program for testing the COM2 serial interface. Characters are sent via the serial interface COM2. The transmission and reception lines (pin 2 -> 5 pin 3 -> 4) are interconnected in a COM4 plug. The sent characters are received again by the COM2.

Declaration

 PROGRAM ComIecLoopBackDemo 
VAR 
   lState: DINT := 1; 
   bStart: BOOL := FALSE; 
   lResultOpen: DINT; 
   lResultWrite: DINT; 
   lResultReadCount: DINT; 
   lResultRead: DINT; 
   lReadCount: DINT := 0; 
   pszRBuffer: STRING := 'PacDriveM'; 
   pszWBuffer: STRING := 'ELAU the Future of Packaging'; 
   lWSize: DINT := 28; 
END_VAR

Program

 CASE lState OF

 1: 
   IF bStart THEN

    lResultOpen := FC_ComIecOpen(_ComIec); lState := 2; END_IF

 2: 
   lResultWrite := FC_ComIecWrite(_ComIec, ADR(pszWBuf fer), lWSize); 
   pszRBuffer := 'PacDriveM'; 
   lState:= 3;

 3: 
   lResultReadCount := FC_ComIecGetReadCount(_ComIec); 
   IF lResultReadCount = lWSize THEN 
      lResultRead := FC_ComIecRead(_ComIec, ADR(pszRBuffer), lWSize); 
      lReadCount := lReadCount + lResultReadCount; 
      IF bStart THEN 
         lState := 2; 
      ELSE 
         FC_ComIecClose(_ComIec); 
         lState := 1; 
      END_IF 
   END_IF 
END_CASE