ABB industrial drive ACS860 basic control procedures

Local control and external control

Transmission has two main controls: external and local. The selection of the control location can be done by using the LOC/REM key on the control panel, or by using the PC tool.

 Local control

When the drive is set to local operation mode, the control instructions are either from the keys on the control panel or from the mount

DriveComposer is issued on the PC tool. For local control, speed and torque control modes can be used;

When the scalar motor control mode is used, the frequency control mode can be used (see Parameter 19.16 Local Control Mode).

Local control is mainly used for commissioning and maintenance. When the control panel is used in local mode, the control panel instructions take precedence over the external control signal source. You can use parameter 19.17 to disable Local control to switch the control mode to the external mode.

The user can select the response of the drive when the communication between the control panel or PC tool and the drive is interrupted by the parameter (49.05 Communication Loss Action). (Parameters have no effect on external control)

 External control

When the drive is under external control, the control instructions are given by:

• I/O ports (digital and analog inputs).

• Embedded fieldbus interface or optional fieldbus adapter module

• External (DDCS) controller interface

• Master/slave link, and/or

• Control panel.

The drive has two external controls, EXT1 and EXT2. Users can use parameter 20.01... 20.10 Set the start and stop instructions for each external control. The operating mode can be selected individually for each external control (parameter group 19 operating modes), allowing free and fast switching between the two external control modes, such as speed and torque control. EXT1 or EXT2 can be activated from any binary source, such as a numeric input or fieldbus control word (see Parameter 19.11 External 1/ External 2 selection). A given source for each running mode can be selected independently.

Use the control disk as the external control source

The control panel can also be used as a start/stop command and/or given signal source in external control. The control disk can be selected in the start/stop command source and given source selection parameters.

The given source selection parameter contains two options for the control disk. The difference between the two options is the initial given after the given source switches to the control panel.

Each time another given source is selected, the control disk Settings are saved. If the given source selection parameter is set to the control disk (a saved given) external 1/ external 2 selection, the saved value can be used as the initial value after the control is switched back to the control disk. Note that only one type of given can be saved at a time: for example, try in different operation modes

Using the same saved setting under formula (speed, torque, etc.) will cause the inverter to trip due to the 7083 control panel given conflict. Control disk Settings can be individually restricted by parameters in group 49 control disk interface communication.

After setting a given source selection parameter to a control disk (a copied given), the initial setting of the control disk depends on whether the mode of operation changes with the given source. If the source switches to the control disk and the mode of operation does not change, the last given from the previous source is taken. If the operating mode changes, the actual value of the inverter corresponding to the new mode is used as the initial value.

The working mode of the transmission

The drive can operate in several different types of given control modes. You can select the control mode for each control place (Local, EXT1, and EXT2) in parameter group 19 Run Mode.

 Rotational speed control mode

The motor rotates at the given speed of the transmission. In this mode, the estimated value can be used as the speed feedback value, and the encoder can be used to obtain higher speed accuracy.

Speed control mode can be used in both local control mode and external control mode. The same applies to vector control and scalar motor control modes.

 Torque control mode

The motor torque rotates according to the torque given by the transmission. Torque control can be feedback-free, but is more dynamic and accurate when used with a feedback device, such as an encoder. Feedback devices are recommended for crane, winch or hoist control.

For both local control mode and external control mode, torque control mode can be used in vector motor control mode.

 Frequency control mode

The motor rotates according to the frequency given by the transmission, and the frequency control is only effective in the scalar motor control mode.

 Special control mode

In addition to the above control modes, the following special control modes can be provided:

• For more information, see Electropotentiometer (page 47).

• Scram modes Off1 and Off3: The drive stops in accordance with a defined deceleration ramp, or modulated stops.

• Point mode: When the point signal is activated, the drive starts and accelerates to the given speed according to the defined acceleration time. For more information, see Point-and-click functions (page 41).