Logix5000 Controllers General Instructions - SLAC Confluence

598 ASCII Serial Port Instructions (ABL, ACB, ACL, AHL, ARD, ARL, AWA, AWT)Example 1:When the temperature exceeds the high limit (temp_high is set), theAWA instruction sends a message to a MessageView terminal that isconnected to the serial port of the controller. The message containsfive characters from the DATA member of the string[1] tag, which is astring. (The $14 counts as one character. It is the hex code for theCtrl-T character.) The instruction also sends (appends) the charactersdefined in the controller properties. In this example, the AWAinstruction sends a carriage return ($0D), which marks the end of themessage.Relay Laddertemp_highAWAASCII Write AppendChannel 0Sourcestring[1]'$1425\1'SerialPort Control temp_high_writeSerialPort Control Length 5Characters Sent 6ENDNERStructured TextIF temp_high THENtemp_high_write.LEN := 5;AWA(0,string[1],temp_high_write);temp_high := 0;END_IF;Publication 1756-RM003I-EN-P - January 2007