DVP-ES2/EX2/SS2/SA2/SX2/SE&TP Operation Manual - Programming previous step is completed, therefore it forms a sequential control process similar to SFC (Sequential Function Chart) mode. The STL sequence can be converted into a PLC ladder diagram which is called “step ladder diagram” as below. M1002 M1002 initial pulse S0 SET S21 S S0 S S21 S21 S S22 e S22 S0 RET 1.5.12 RET (Return) RET instruction has to be placed at the end of sequential control process to indicate the completion of STL flow. e S S20 RET e S S20 RET Note: Always connect RET instruction immediately after the last step point indicated as the above diagram otherwise program error may occur. 1-8 SET S0 SET S22