RUN EXCITE: Service & Maintenance Manual - rev. 1.5
To actuate the motor, the digital plan board communicates over the RS-485 serial link with the
inverter through the download board. Based on the commands received, the inverter outputs 2
appropriate digital signals (enable motor signal and direction signal) to the elevation board for
actuating the elevation motor.
When the elevation board receives the Enable signal which enables motor movements, based on the
value of the Up/Down direction signal it applies a +24 or -24 Vdc voltage to the motor, causing the
relay on the board to switch accordingly.
To control the incline position, the machine is equipped with:
• a Limit switch which defines a zero-reference position, acquired by the machine during its
power-on reset procedure;
• an encoder consisting of a Hall effect sensor integrated into the elevation motor: when the
motor is running it outputs train of pulses which represent the motor movement.
Both signals are received by the elevation board and sent to the inverter. The inverter counts the
pulses received and is thus able to determine the exact position of the incline. When the target
position is reached, the inverter disables the elevation motor movement.
The inverter monitors the correct functioning of the encoder. When the command for enabling
elevation motor movements is asserted, if no pulses arrive for a time period of approximately 100
msec, the inverter locks out with error code “EdC”. The machine displays the error message
“GRADIENT NOT WORKING” and halts all movements of both the elevation and tread belt
motors. If the machine is turned off and on again, it will resume operation with only the tread belt
motor enabled. Elevation motor movements can only be resumed, obviously after having resolved
the problem, by resetting the parameter PAR 07 to 0.
3.3.3. THE RESET PROCEDURE
On power-up, the machine performs a reset procedure in order to determine the zero-reference
position for the incline. The procedure consists of the downward movement of the machine until the
Limit switch is tripped. This defines the reference “zero position” for the incline: all movements for
reaching different elevations will variations relative to this reference.
3.3.4. THE SIGNALS INVOLVED
The machine uses the following control signals:
• RS-485 Signal
This is a digital signal exchanged between the inverter and the digital plan board. There is no
way to monitor its state other than through the LEDs on the Download board.
• Enable signal
This is the signal generated by the inverter (pins 35-6) to enable movements of the elevation
motor. This signal is normally at 0 Vdc when the elevation motor is stopped, and it goes to –24
Vdc to actuate the motor. This signal remains at -24 Vdc for the entire duration of the
movement.
The signal enters the elevation board (pins 3-1 of connector X5) and enables the movement.
Page 3.15
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