How to impose a character count with real time counter.
1. Create a long text type question.
2. In the Help box (below the question text box), enter the following text (replace 1000 characters with your limit)
Maximum Allowed: 1000 characters. Currently Used: {strlen(self)} characters.
3. Go to the panel at right called "Advanced settings" and find the heading "Input" and set Maximum characters to your character maximum.