Activity Chart Checks : (C3139) Illegal switch structure: non-unique selected entries

(C3139) Illegal switch structure: non-unique selected entries

Error In:
Correctness
Description:
Switch/Case structures within an activity’s mini-spec have non-unique entries.
Example:
Activity ACT_1 contains the following mini-spec:
ch(SWITCH_VAL)/switch_c (SWITCH_VAL) {
case_c 1: OUT1=RED;break;
case_c 2: OUT1=AMBER;break;
case_c 2: OUT1=GREEN;break;
default : OUT=AMBER;}
 
The error is generated because two statements reference case_c=2.
Erroneous Elements:
Switch/Case structures