MODBUS Slave

Slave Status This block provides the number of received requests and the sent responses. Furthermore it shows the number of potentially appearing CRC errors. Parameters None Signals Name I/O Type(s) Function Request O WORD Number of received requests Answer O WORD Number of responses CRCErr O WORD Number of detected checksum errors

Register/Coil Write Access This block enables the configuration of register addresses for which the master has writing access. According to the data model “Modbus”, “Coils” and “Holding Register” are supported. Addressing is 0 based. In the block, up to 8 objects can be indicated. The I/O modules, which are accessible on the hardware, and the freely definable process variables are supported. This function block is the interface between the variables and the I/Os to the Modbus. The block does ...

Register/Coil Read Access This block enables the configuration of register addresses for which a master has reading access. According to the data model “Modbus”, “Discrete inputs”, “Coils”, “Input register” and “Holding register” are supported. Addressing is 0 based. In the block, up to 8 objects can be indicated. The I/O modules, which are accessible on the hardware, and the freely definable process variables are supported. This function block is the interface between the variables and the I...

MODBUS Slave Configuration 1. Basic Configuration The basic characteristics of the Modbus RTU slaves are determined in a dialog, which is accessible over the tools menu. Here, the slave address and the baud rate are defined. Further settings of the serial interface are fixed (no parity, 1 stopbit). Furthermore address offsets for “Holding register” and/or “Coils” can be defined. Be aware, that these offsets are added automatically on the already assigned addresses. With very high addresses, ...