Special Characteristics of the ACS Drives Base Library

The types and constants defined in this library are base types and can be used in other ACSDrivesXXX libraries, e.g. ACSDrivesComModRTU_AC500_V20.lib.

The ACSDrivesBase_AC500_V20 Library includes 3 different control Function Blocks to be used with ACS drives configured for ABB Drives Profile.

For three of these blocks the communication to the drive is made via the DRIVE_DATA variable which must be connected to an communication Function Block. The communication Function Blocks for different fieldbuses can be found in separate libraries, e.g. ACSComModRTU_AC500_V20.lib for MODBUS RTU connection.

One control Function Block (ACS_DRIVES_CTRL_STANDARD_GEN) is a generic block which doesn´t need a communication block. The input of Status Word and output of Control Word must be mapped somehow to any fieldbus.

The control Function Blocks work independent of the used fieldbus connection. The principle and differences of the 4 control blocks is shortly described below:

ACS_DRIVES_CTRL_ENG

The ACS_DRIVES_CTRL_ENG Function Block is designed for user specific control of the drive setting the Control Word (CW) by the user in the program.

Therefore the user should have a detailed knowledge of the ABB Drives Profile handling.

The reference and actual values must be given in fieldbus equivalent, e.g. +/- 20000 for the reference value 1.

ACS_DRIVES_CTRL_STANDARD

The ACS_DRIVES_CTRL_STANDARD Function Block can be used for standard control functions.

The handling of the ABB Drives Profile State Machine is done inside the block. The Control Word is built according to ABB Drives Profile State Machine, the Status Word (SW) and the inputs of the Function Block.

The reference and actual values must be given in fieldbus equivalent, e.g. +/- 20000 for the reference value 1.

ACS3XX_DRIVES_CTRL_BASIC

The ACS3XX_DRIVES_CTRL_BASIC Function Block is designed especially for ACS3XX and ACX550 drives and provides additionally scaling functions for the speed reference.

The handling of the ABB Drives Profile State Machine is done inside the block. The Control Word is built according to ABB Drives Profile State Machine, the Status Word (SW) and the inputs of the Function Block.

The speed reference input can be given in rpm or in 0.1 Hz. The act speed output is also in rpm or 0.1 Hz.

ACS_DRIVES_CTRL_STANDARD_GEN

The ACS_DRIVES_CTRL_STANDARD_GEN Function Block can be used for standard control functions, using any generic fieldbus.

The handling of the ABB Drives Profile State Machine is done inside the block. The Control Word is built according to ABB Drives Profile State Machine, the Status Word (SW) and the inputs of the Function Block.

The block does not have a DRIVE_DATA input. The SW and CW can be retrieved from any where. So any generic fieldbus can be used to get the SW and send the CW to the drive.

The block does not have any input or output for actual- or reference speed values. These can be send directly via the fieldbus to the drive.

ACS_REF_SCALING

This block can be used to scale the actual and reference values from fieldbus equivalent (+/- 20000 or +/- 10000) to the physical value (“rpm” or “Hz”).

Picture bellow shows an overview for the speed values. Same functionality is also provided in the same block for the torque values.

This block can also be used together with other ACS or DCS blocks, e.g. ACS_DRIVES_CTRL_STANDARD or DCS_DRIVES_CTRL to scale the fieldbus values to physical values used in the PLC program.