Manual

4. Operation Using I/O Signals

 Torque-limit Selection Signal (TL)

This signal limits the motor torque.

While this signal is ON, the actuator thrust (motor torque) is limited to the torque set in User Parameter No. 57

(Torque limit).

Caution: z Do not turn the TL signal OFF while it is ON.

z Excessive deviation (standing pulses) may generate while torque is limited (while the TL signal is

ON) (for example, when the actuator receives load and is prevented from moving just like in

push-motion operation).

If the TL signal is turned OFF in this condition, the controller will instantly start controlling the

actuator at the maximum torque and the actuator may move suddenly or run out of control.

This signal can be disabled using User Parameter No. 61 (Torque-limit command input). Disable the TL signal if it is

not used.

 Homing Signal (HOME)

This command signal is used to perform homing automatically.

The homing command is processed at the leading edge (ON edge) of the HOME signal to cause the actuator to

return to its home automatically.

When the homing is completed, the HEND (homing complete) output signal turns ON.

Program the host controller (PLC) so that its current-value register will be reset to the home (“0” will be input to the

* This signal is always enabled as long as the servo is on.

* Even after homing has been performed once, homing can be performed again by turning the HOME signal ON.

Caution: z The HOME signal is given priority over pulse train commands. Even while the actuator is

moving under a pulse train command, it will start moving to the home once the HOME signal is

turned ON.

z The HOME signal is processed only at its leading edge (ON edge).

z If the SON signal turns OFF or an alarm is detected during homing, the homing operation will

stop. If the servo turns off, the homing command will be cancelled even if the HOME signal is

still ON. To perform homing again, turn the HOME signal OFF, and then turn it back ON.

z The actuator can be operated without using this function. If this function is not used, however,

all management actions over position data will be left to the host controller.

In this case, take necessary measures to prevent an over-stroke error, such as not sending

pulse commands exceeding the effective stroke, or providing external limit switches or other

devices for detecting stroke ends to forcibly stop the actuator upon detection of a stroke end.

z This controller has a command pulse counter. After homing, the controller

increments/decrements command pulses and performs positioning based on command pulse

data.

However, the command pulse counter cannot be used if this function is not used. Without this

function, the position where the actuator is currently stopped is used as the origin and the

actuator will move from there by the number of pulses input (incremental movement). If

incremental movement is repeated, positioning errors generating in individual positioning

operations will accumulate and the actuator may end up not stopping at the final target position.

To prevent this problem, periodically execute homing from the host controller or take other

appropriate measures.