Logix5000 Controllers General Instructions - SLAC Confluence

ASCII Serial Port Instructions (ABL, ACB, ACL, AHL, ARD, ARL, AWA, AWT) 587ASCII Read (ARD)The ARD instruction removes characters from the buffer and storesthem in the Destination.Operands:Relay LadderARDASCII ReadChannel ?Destination ???SerialPort Control ?SerialPort Control Length ?Characters Read ?ENDNEROperand Type Format Enter NotesChannel DINT immediate 0DestinationSerial PortControlSerial PortControl LengthstringSINTINTDINTSERIAL_PORT_CONTROLtagtagtagtag into which thecharacters are moved(read):• For a string data type,enter the name of thetag.• For a SINT, INT, or DINTarray, enter the firstelement of the array.tag that controls theoperationDINT immediate number of characters tomove to the destination(read)• If you want to compare, convert, ormanipulate the characters, use a string datatype.• String data types are:• default STRING data type• any new string data type that you create• The Serial Port Control Length must be lessthan or equal to the size of the Destination.• If you want to set the Serial Port ControlLength equal to the size of the Destination,enter 0.Characters Read DINT immediate 0 During execution, displays the number ofcharacters that were read.Structured TextARD(Channel,Destination,SerialPortControl);The operands are the same as those for the relay ladderARD instruction. However, you specify the Serial Port Control Lengthand the Characters Read values by accessing the .LEN and .POSmembers of the SERIAL_PORT_CONTROL structure, rather than byincluding the values in the operand list.Publication 1756-RM003I-EN-P - January 2007