Max Machinery 120 FLOW RATE & TOTAL INDICATOR - Manual (Page 2)

Page 2 120-200-350 © 1993 (Rev 5/97) Max Machinery, Inc.
General Description
The Max 120 Flow Rate & Total Indicator performs two basic functions. It totalizes all flow
and calculates flow rate.
Totalizer
The totalizer has a ten digit display, and is equipped with a scaler to accept flow meter
K-factor values from 0.0001 to 99999. The Reset key can be programmed to reset the
totalizer count. The totalizer inhibit input can be used to stop the count. The totalizer is
unidirectional; it counts up only.
Two transistor outputs are available from the totalizer. Transistor 1 provides a scaled output
pulse for each count of the totalizer display. The pulse output duration can be programmed
for Fast (125
µ
sec), Medium (2 msec.) or Slow (50msec.). The totalizer has a buffer capable
of storing 255 scaled counts if the totalizer count rate temporarily exceeds the scaled output
rate. If the buffer capacity is exceeded, pulses will be lost from the scaled pulse output, and
the message PULSE OVERFLOW will appear on the display. The contents of this buffer are
saved if the power is removed from the unit before all of the counts have been output. This
buffer is reset when the totalizer is reset.
Transistor 2 is the totalizer setpoint output which turns on when the totalizer count reaches
the totalizer setpoint. The output can be programmed to time out (turn off) from 0.01 to 99.99
seconds after it turns on. Programming the timer to a value of 0.00 disables the timer and
causes the output to remain on until an input or keyboard command unlatches it. This
setpoint can be used to perform a batching function.
Rate Indicator
The rate meter has six digits of display and calculates flow by measuring the time interval
between input pulses or average time between groups of pulses and then reciprocating the
time. The reciprocated time is multiplied by the flow meter K-factor and a rate multiplier
(Rm) to provide rate readings in the desired units of measure.
The smoothing function allows the rate indicator to average rate readings from 1.0 seconds to
7.5 seconds in 0.5 second steps. There is no smoothing when programmed for 0.5 seconds.
The rate hi and lo setpoints are used to set rate values at which the rate alarm outputs turn on.
The hi output is turned on if the rate is greater than the hi setpoint, the lo output is turned on
if the rate is lower than the lo setpoint. The outputs can be programmed to follow, time out,
or to latch until a keyboard or input signal is received. In the follow mode of operation, the
rate is compared to the hi and lo setpoints after each rate update. If an output is turned on, it
remains on until the next rate update occurs and then is either left on or turned off depending
on the comparison of the new rate reading with the setpoints. In the time out mode of
operation, the outputs can be programmed to turn on for 0.01 to 99.99 seconds. Programming
a value of 0.00 disables the timer and causes the outputs to latch until unlatched by a
keyboard or input signal.
GENERAL DESCRIPTION