Control System
26
Service Manual – Focus II / Scrubtec R6 Rider Autoscrubber
Sample Shop Voltage Measurements
Examining signals sent and received at the control board can be very effective in determining if external
components are functioning as expected or if the control board is processing them as expected. The tables
below show sample voltage measurements taken from a Focus machine. Actual voltages will vary from
machine to machine, and with battery charge level.
The majority of voltage measurements will be dependant on the battery voltage of the machine at the time.
The nominal battery voltage is 24 volts, but depending on the charge state of the battery, the actual voltage
may be higher or lower. With regard to digital logic signals, the terms “High (voltage)” and “Low (voltage)”
mean a voltage value equal (or close to) Battery-Positive and Battery-
Negative, respectively. V
CC
is a special voltage value that is independent of the
battery voltage, and is regulated to be close to 5.0 volts by the Main Machine
Controller’s circuit board.
Some signals are Pulse-Width Modulated (PWM) This means that these
signals are being turned On and Off at a high rate. Even though their
instantaneous voltage jumps from 24V to 0V, your voltmeter will average these
On/Off jumps into an equivalent voltage somewhere in between 24 and 0 volts.
The “
≈
“ symbol means “approximately”.
To aid in taking voltage measurements from the cable connectors without
removing the connector, a T-shaped push pin connected to the voltmeter probe
wire works well (see image to the right).
Main Machine Controller Sample Voltage Measurements at the J1 Connector
Pin #
Name
V-On V-Off Ref. Comments
J1-1 Det Pmp+
≈8
2.16
B-
PWM output to detergent pump between J1-1 and J1-3
≈5
0
J1-3
J1-2 Not Used
J1-3 Det Pmp+
≈8
2.16
B-
PWM output to detergent pump between J1-1 and J1-3
≈5
0
J1-1
J1-4
Deck Lift+
(Raise)
0.2
2.2
B-
Differential output for the deck actuator. When inactive, the difference
between J1-4 and J1-5 is zero. When active, the difference between
J1-4 and J1-5 is just below battery voltage, and reverses polarity
depending on the direction.
-22.1 0
J1-5
Deck Lift+
(Lower)
24.3 2.2
B-
22.1 0
J1-5
J1-5
Deck Lift-
(Raise)
24.3 2.2
B-
22.1 0
J1-5
Deck Lift-
(Lower)
0.2
2.2
B-
-22.1 0
J1-5
J1-6 Not Used
J1-7 Not Used
J1-8
B-
0.06
0
B- Voltage drop should remain low for all functions
J1-9
Sq Lift+
(Raise)
0.3
2.2
B-
Differential output for the squeegee lift actuator. When inactive, the
difference between J1-4 and J1-5 is zero. When active, the difference
between J1-4 and J1-5 is just below battery voltage, and reverses
polarity depending on the direction.
-21.7 0
J1-5
Sq Lift+
(Lower)
23.9 2.2
B-
21.7 0
J1-5
J1-10
Sq Lift-
(Raise)
23.9 2.2
B-
21.7 0
J1-5
Sq Lift-
(Lower)
0.3
2.2
B-
-21.7 0
J1-5
T-Pin
Probe Wire
J1
J2
