5. Position Control Parameter

This servo supports position control commands via PWM or CAN communication. You must select one of the two methods for use, and the default setting is CAN communication.

5.1 With CAN Mode

(a) Position Command : (+) drives in the CW direction, and (-) drives in the CCW direction, which can be changed by adjusting the DIRECTION(Addr:152d).

Figure 3. Control Direction

(b) The Neutral Position can be modified through the User Configuration Parameter settings.

(1) User Configuration Parameter settings can be referenced in Table 7, OFFSET Parameter (Addr:18d).

(2) The default Neutral Position is 0[deg], and it can be adjusted up to ±90[deg].

(c) The Travel Range can be operated up to ±170[deg] through the User Configuration Parameter settings.

(d) The motor driver transitions the BLDC motor to an electrical braking state using FET shorting if no position command is detected for a duration exceeding 200[ms].

Figure 4. Travel Range on CAN Mode

5.2 With PWM Mode

(a) The SMR12-GT7.0 can perform position control using an external PWM signal (refer to Figure 3).

(1) The PWM signal allows a voltage level range of 3.3[V] to 5.0[V] and a pulse width range of 0.9[ms] to 2.1[ms], with a deadband of 0.1[us].

(2) In PWM interface mode, the travel range is fixed to ±60.0[deg].

Figure 5. Travel Range on PWM Mode

(b) The Neutral Position can be modified through the User Configuration Parameter settings (refer to Figure 4).

(1) User Configuration Parameter settings can be referenced in Table 7, OFFSET Parameter (Addr : 18d).

(2) The PWM 1.5[ms] interval corresponds to the Neutral Position (Default 0[deg]), and it can be adjusted up to ±90[deg] based on the offset setting.

Figure 6. PWM Signal Characteristics

(3) The travel range can be operated as ±60[deg] (fixed) around the Neutral Position.

(4) The motor driver transitions the BLDC motor to an electrical braking state using FET shorting if no position command is detected for a duration exceeding 200[ms].