Measurement Computing eZ-TOMAS version 7.1.x - Manual (Page 35)

eZ-TOMAS & eZ-TOMAS Remote 887591 Edit Menu 3-9
Tach Section of the Input Channels Tab
Rotation is the shaft’s rotation direction, either clockwise or counter-clockwise. The direction
indicated is as viewed from the driver end of the machine train.
Pulse/Rev is the number of pulses per 360 degree revolution. (Default: 1)
RPM Mult. Used to enter an RPM multiplier value. This is useful if your tachometer is measuring an
RPM that is proportional to another value of interest, such as in a gear train. For
example, you want to see the RPM for shaft “X” which is known to turn at 2.5 times the
RPM of gear “Z;” but it is impractical for a tachometer to measure the RPM of the shaft
by any direct means. In this case, we would enter a multiplier of 2.5 for the gear’s RPM
to obtain the shaft’s RPM.
Auto Tach If a Analog Input Channel is defined as a Tachometer Input. You can either manually
specify a trigger level or use the Auto-Tach detection option.
During acquisition eZ-TOMAS can automatically detect and adjust the analog tach’s
trigger settings. This can be useful when the tach signal changes voltage levels during
machine operation.
Trig Dir is the “negative’ [down arrow] or “positive” [up arrow] direction of the moving shaft.
Trig Volt defines the Tach pulse for tach signals. A keyway will generate a Negative Tach pulse.
Typical Tach signals will generate at least a 1 V pulse. You can check the voltage value
using a Time display.
Mode Used to select one of three available modes: Voltage, Counter, or Period.