RoboteQ AX2550/2850 ユーザーズマニュアル
Closed Loop Position Mode
120
AX2500/2850 Motor Controller User’s Manual
Version 1.7. February 1, 2005
The second method uses the AX2500/2850’s Emergency Stop input to shut down the con-
troller if any of the limit switches is tripped. Figure 72 shows the wiring diagram used in
this case. Each of the limit switches is a Normally Open switch. Two of these switched are
typically required for each motor. Additional switches may be added as needed for the sec-
ond motor and/or for a manual Emergency Stop. Since very low current flows through the
switches, these can be small, low cost switches.
troller if any of the limit switches is tripped. Figure 72 shows the wiring diagram used in
this case. Each of the limit switches is a Normally Open switch. Two of these switched are
typically required for each motor. Additional switches may be added as needed for the sec-
ond motor and/or for a manual Emergency Stop. Since very low current flows through the
switches, these can be small, low cost switches.
The principal restriction of this technique is that it depends on the controller to be fully
functioning, and that once a switch is activated, the controller will remain inactive until the
switch is released. In most situations, this will require manual intervention. Another limita-
tion is that both channels will be disabled even if only one channel caused the fault.
functioning, and that once a switch is activated, the controller will remain inactive until the
switch is released. In most situations, this will require manual intervention. Another limita-
tion is that both channels will be disabled even if only one channel caused the fault.
Important Warning
Limit switches must be used when operating the controller in Position Mode. This
will significantly reduce the risk of mechanical damage and/or injury in case of dam-
age to the position sensor or sensor wiring.
will significantly reduce the risk of mechanical damage and/or injury in case of dam-
age to the position sensor or sensor wiring.
Using Current Limiting as Protection
It is a good idea to set the controller’s current limit to a low value in order to avoid high cur-
rent draws and consequential damage in case the motor does not stop where expected.
Use a value that is no more than 2 x the motor’s draw under normal load conditions.
rent draws and consequential damage in case the motor does not stop where expected.
Use a value that is no more than 2 x the motor’s draw under normal load conditions.
Control Loop Description
The AX2500/2850 performs the Position mode using a full featured Proportional, Integral
and Differential (PID) algorithm. This technique has a long history of usage in control sys-
tems and works on performing adjustments to the Power Output based on the difference
measured between the desired position (set by the user) and the actual position (captured
by the position sensor).
and Differential (PID) algorithm. This technique has a long history of usage in control sys-
tems and works on performing adjustments to the Power Output based on the difference
measured between the desired position (set by the user) and the actual position (captured
by the position sensor).
Motor
SW1
SW2
Manual
Emergency
Stop Switch
Emergency
Stop Switch
Emergency Stop Input
Ground
AX2550
FIGURE 72. Safety limit using AX2500/2850’s Emergency Stop input