RB433 - No voltage indicator

Hi there

Why does the voltage, under ‘System/Health’ show 0.0V on my RB433? On the RB433AH’s its fine?

Thx.

Look here for the more information,
http://forum.mikrotik.com/t/script-for-hourly-voltage-monitor-via-email-rb333-rb433ah/23372/2

Thx, appreciated.