Table of Contents

Sending e-mails – ST – from more accounts

Block name

SENDMAILCUSTOM

ST call

PROGRAM TEST_SENDMAILCUSTOM
 VAR
        TESTEMAIL : BOOL :=TRUE;
    HOST : STRING[64] := 'SMTP.DOMAT.CZ';
       PORT : UINT := 25;
      USER : STRING[64] := 'INFO@DOMAT.CZ'; 
      PASSWORD : STRING[64] := '1234';
    SENDER : STRING[64] := 'INFO@DOMAT.CZ';
     RECIPIENT : STRING[64] := 'SUPPORT@DOMAT.CZ';   
        SUBJECT : STRING[64];
       MESSAGE : STRING[64]; 
 END_VAR
 
 IF TESTEMAIL THEN
    SUBJECT := 'TEST';
  MESSAGE := 'TEST EMAIL HAS BEEN SENT.';
     MESSAGING.SENDMAILCUSTOM(HOST, PORT, USER, PASSWORD, SENDER, RECIPIENT, SUBJECT, MESSAGE);
       TESTEMAIL := FALSE;
 END_IF;
END_PROGRAM

Library

MESSAGING

Version

V1.0

Description

The function sends an e-mail in each PLC computing cycle. It is highly recommended to be used in ST code only to prevent occassional flooding of the recipient with many e-mails of the same contents. Using this function, it is possible to specify the e-mail sender account and credentials in the program (this is not possible with functions sendmail and sendmailtrig where these data are entered in the channel definition).  If You want to send more than one email at the time, You have to use this block multiple times or create some sort of switcher for addresses. PLC is capable of sending one email at the certain moment, so more emails needs to be sent with gaps. The gap between emails should be at least 1 second, but ideally even more.  

Inputs

Input Type Description
HOST STRING_REFreference to variable with the SMTP server name
PORT UINT TCP port number where the SMTP server is listening
USERNAMESTRING_REFreference to variable with user name used to access the SMTP server
PASSWORDSTRING_REFreference to variable with password used to access the SMTP server
CHANNEL STRING_REFreference to variable with the communication connection definition (set in PLC properties, see below)
FROM STRING_REFreference to variable with e-mail address from which the mail is sent
TO STRING_REFreference to variable with the recipient's address
SUBJECT STRING_REFreference to variable with the e-mail subject
MESSAGE STRING_REFreference to variable with the e-mail body text

Outputs

OutputTypeDescription
SINTNumeric status; result of the system settings check

Function

At each of the function calls, a e-mail is sent from the predefined from e-mail account username to the to address. The e-mail subject is taken from the subject variable, and the e-mail body from the message variable.

This function has not defined the connection parameters for the SMTP server in the Channel definition. The connection parameters must be defined in the variables which are linked to the host, port, username, and password inputs. This means that the parameters may be changed by the application program, and the user account name may be different for different e-mail messages. 

Remember to coeck the SMTP server availability from the network where the PLC is running. 

The output variable result indicates the result of the system settings check.

ValueDescription
0 OK
8 E-mail queue full
16 Unknown channel
24 Error - impossible to determine the status
otherInternal error - contact Domat Control System support


Application example


This function is typically used to send alarm messages. The sending of an e-mail is launched by the alarm status appearance. See the ST call above for example.