29. TACHOGRAPH (TCO 15-6) 29.1 EXPLANATION OF COMPONENTS 1. INSTRUMENT LOCK This can be used for the instrument lock key when replacing the charts, or for operator change identification keys 1 and 2. 2. CLOCK DIAL One line indicates one minute. 3. CLOCK OPERATION CONFIRMATION APERTURE It is possible to check the action of the second hand when the clock is working. 4. SPEED SCALE This is the scale for the machine travel speed. 5. SPEED INDICATOR This indicates the machine travel speed. 6. SPEED WARNING LAMP When the machine exceeds the maximum set speed, the lamp lights up to warn the operator. Models with the speed warning lamp do not have the speed indication confirmation lamp. 5-16