Technogym Forma Service Maintenance Manual page 32

• Motor voltage signal (Vdc)
This is the DC voltage generated by the driver board (pin 1-2 of connector J1) to supply the up-
down motor. Its absolute value is 24 Vdc, and the motor will rotate either clockwise or
anticlockwise depending on its polarity, causing the rod to become longer or shorter, thereby
increasing or decreasing the machine incline.
• Pulse signal
This is a square wave signal alternating between logic level low (8.8 Vdc) and logic level high
(11.4 Vdc), generated by the hall sensor incorporated into the motor. This signal reaches the
driver board (pin 5-6 on connector J1).
The signal is level-converted, filtered, squared and output (pin 9-11 on connector J6) to the CPU
board (pin 9-11 on connector K4) for controlling the movement. The output signal is still a
square wave signal, but alternating between 0 and 5 Vdc.
• Alarm signal
This is the signal generated by the driver board (pin 7-12 on connector J6) when it detects a
motor overcurrent condition. This signal is sent to the CPU board (pin 7-12 on connector K4).
As soon as the CPU board receives this signal, it resets the up or down command which caused
the alarm condition, to protect the motor from damage due to overcurrent.
The control logic enables the weight stack motor interface board to freely drive the motor when
the alarm signal is at logic level high (5 Vdc). As soon as this signal goes low ( 0 Vdc) the CPU
board resets the previously asserted up or down motor signal, causing the weight stack motor
interface board to reset the alarm signal, which thus returns high. All this takes place within a
few msec.
Page 3.10
FORMA: Service & Maintenance manual - rev. 3.0