[SOLVED] Writing array tag to INT in Structured Text in PLC Logic

Writing array tag to INT in Structured Text in PLC Logic

I'm new to PLC logic and would like to know a more efficient way to change the following statement.

A is INT, B is an array of INT.

IF COUNT = 1 THEN A := B[0];
ELSIF COUNT = 2 THEN A := B[1];
ELSIF COUNT = 3 THEN A := B[2];
ELSIF COUNT = 4 THEN A := B[3];
ELSIF COUNT = 5 THEN A := B[4];
ELSIF COUNT = 6 THEN A := B[5];
ELSIF COUNT = 7 THEN A := B[6];
ELSIF COUNT = 8 THEN A := B[7];
ELSIF COUNT = 9 THEN A := B[8];
ELSIF COUNT = 10 THEN A := B[9];
ELSIF COUNT = 11 THEN A := B[10];
ELSIF COUNT = 12 THEN A := B[11];
ELSIF COUNT = 13 THEN A := B[12];
ELSIF COUNT = 14 THEN A := B[13];
ELSIF COUNT = 15 THEN A := B[14];
ELSIF COUNT = 16 THEN A := B[15];
END_IF;

Solution

IF COUNT>=1 AND COUNT<=16 THEN
  A := B[COUNT-1];
END_IF

The IF statement is not necessary but ensures that you don't put an invalid array index into B if COUNT gets out of range.