ACS_MOD_READ_N_PRM Read N Parameters from an ACS Drive via MODBUS RTUΒΆ

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Function Block ACS_MOD_READ_N_PRM is used for reading n parameters from a drive via MODBUS.

Function Block Information

Available in PLC runtime system: V1.3.2
Included in library: ACSDrivesBase_AC500_V20.lib
Function Block Type: Function Block with historical values.

Block Description

Function Bock ACS_MOD_READ_N_PRM reads n parameters of the drive. The number of parameters to be read is specified at the input NVAR. The first parameter number is specified at the input PRM_NUM. All parameters must be accessible from consecutive MODBUS registers in the drive. The values of the parameters are stored in the PLC memory area, defined at the input DATA. The values in the PLC memory area are updated when the read job was performed without error. This is indicated by DONE=TRUE and ERR=FALSE.

As long as the EN = TRUE a new read job is requested each time the further read job is terminated.

The MODBUS job is started from the Communication Block which is connected to the same DRIVE_DATA variable. It uses the MODBUS function code 03 (Read n words).

The drive (MODBUS slave) from which the parameter is read is specified at this Communication Block.

The Communication Blocks are available from other ACSDrivesComXXX libraries e.g. ACS_3XX_COM_MOD_RTU ACS3XX_COM_MOD_RTU Communication for ACS3XXwrite one bit/ACX550 Drives via MODBUS RTU in ACSDrivesComModRTU_AC500_V20.lib. ACS / DCS Drives Communication via MODBUS RTU Library or ACS_COM_MOD_TCP_ENHANCED ACS_COM_MOD_TCP_ENHANCED Communication for ACS / DCS Drives via MODBUS TCP in ACSDrivesComModTCP_V22.lib ACS / DCS Drives Communication via MODBUS TCP LibraryACS_COM_MOD_TCPx_ENHANCED ACS_COM_MOD_TCPx_ENHANCED Communication for ACS / DCS Drives via MODBUS TCP in ACSDrivesComModTCP_Ext_AC500_V24.lib.

Note

If the connected communication block (via DRIVE_DATA variable) is disabled or not parametrized correctly and EN = TRUE, the variables or arrays that are attached via DATA input are reset to zero. This can be checked by the ERNO output.