Data Access Reading Input Registers / Read Holding Registers (FC03 / FC04) With this function code one or more 16-bit values can be read. This function can be used with the NanoJ objects (see "NanoJ Objects") or process data objects (minimum 4 byte alignment, see Process data objects (PDO) for details). Request Name Length Value Slave Address 1 Byte Function code 1 Byte 03h Starting Address 2 Bytes 0000h to FFFFh Quantity of Registers 2 Bytes 1 to 7Dh (125d) CRC 2 Bytes Response ("M" being the number of registers to read) Name Length Value Slave Address 1 Byte Function code 1 Byte 03h Byte count 1 Byte 2 * M Register value 2 Bytes CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 83h Exception code 1 Byte 01, 02, 03 or 04 CRC 2 Bytes Example Here is an example of a request to read register 5000 (1388h) and the following register (=2 registers): Request Response Write Single Register (FC06) With this function code one 16-bit value can be written. This function can be used with the PDO area (see Process data objects (PDO)). Request Name Length Value Slave Address 1 Byte Function code 1 Byte 06h Register Address 2 Bytes 0000h to FFFFh Register Value 2 Bytes 0000h to FFFFh CRC 2 Bytes Response Name Length Value Slave Address 1 Byte Function code 1 Byte 06h Register Address 2 Bytes 0000h to FFFFh Register Value 2 Bytes 0000h to FFFFh CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 86h Exception code 1 Byte 01, 02, 03 or 04 CRC 2 Bytes Example Here is an example of a request/response to write the value "0001" to register 6000 (1770h): Request Response Write Multiple Registers (FC16) With this function code one or more 16-bit values can be written. This function can be used with the NanoJ objects (see "NanoJ Objects") or process data objects (see Process data objects (PDO) for details). Request ("N" being the number of registers to write) Name Length Value Slave Address 1 Byte Function code 1 Byte 10h Starting Address 2 Bytes 0000h to FFFFh Quantity of Registers 2 Bytes 0001h to 007Bh Byte Count 1 Byte 2 * N Registers Value N * 2 Bytes CRC 2 Bytes Response Name Length Value Slave Address 1 Byte Function code 1 Byte 10h Starting Address 2 Bytes 0000h to FFFFh Quantity of Registers 2 Bytes 0001h to 007Bh CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 90h Exception code 1 Byte 01, 02, 03 or 04 CRC 2 Bytes Example Here is an example of a request to write the values "0102h" and "0304h" starting at the register 6000 (1770h), number of registers is 2, length of the data 4: Request Response Report server ID (FC17) With this function code the description of the type, status and other information of the device can be read. Request Name Length Value Slave Address 1 Byte Function code 1 Byte 11h CRC 2 Bytes Response Name Length Value Slave Address 1 Byte Function code 1 Byte 03h Byte count 1 Byte 01h Run Indicator Status 1 Byte 00h = OFF, FFh = ON Additional Data CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 91h Exception code 1 Byte 01 or 04 CRC 2 Bytes Example Here is an example of a request and response to report the ID and status: Request Response Read/Write Multiple registers (FC23) With this function code one or more 16-bit values can be read and written at the same time. This function can be used with the NanoJ objects (see "NanoJ Objects") or process data objects (see Process data objects (PDO) for details). Request ("N" being the number of registers to write) Name Length Value Slave Address 1 Byte Function code 1 Byte 17h Read Starting Address 2 Bytes 0000h to FFFFh Quantity to Read 2 Bytes 0001h to 0079h Write Starting Address 2 Bytes 0000h to FFFFh Quantity to Write 2 Bytes 0001h to 0079h Write Byte Count 1 Byte 2 * N Write Registers Value N * 2 Bytes CRC 2 Bytes Response ("M" being the number of registers to write) Name Length Value Slave Address 1 Byte Function code 1 Byte 17h Byte count 1 Byte 2 * M Read Registers value M * 2 Bytes CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 97h Exception code 1 Byte 01, 02, 03 or 04 CRC 2 Bytes Example Here is an example of a request to read six registers starting at register 4, and to write three registers starting at register 15: Here is an example of a request to read two registers starting at 5000 (1388h) and a write to two registers at 6000 (1770h) with 4 bytes and the data "0102h" and "0304h": Request Response
Data Access Reading Input Registers / Read Holding Registers (FC03 / FC04) With this function code one or more 16-bit values can be read. This function can be used with the NanoJ objects (see "NanoJ Objects") or process data objects (minimum 4 byte alignment, see Process data objects (PDO) for details). Request Name Length Value Slave Address 1 Byte Function code 1 Byte 03h Starting Address 2 Bytes 0000h to FFFFh Quantity of Registers 2 Bytes 1 to 7Dh (125d) CRC 2 Bytes Response ("M" being the number of registers to read) Name Length Value Slave Address 1 Byte Function code 1 Byte 03h Byte count 1 Byte 2 * M Register value 2 Bytes CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 83h Exception code 1 Byte 01, 02, 03 or 04 CRC 2 Bytes Example Here is an example of a request to read register 5000 (1388h) and the following register (=2 registers): Request Response Write Single Register (FC06) With this function code one 16-bit value can be written. This function can be used with the PDO area (see Process data objects (PDO)). Request Name Length Value Slave Address 1 Byte Function code 1 Byte 06h Register Address 2 Bytes 0000h to FFFFh Register Value 2 Bytes 0000h to FFFFh CRC 2 Bytes Response Name Length Value Slave Address 1 Byte Function code 1 Byte 06h Register Address 2 Bytes 0000h to FFFFh Register Value 2 Bytes 0000h to FFFFh CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 86h Exception code 1 Byte 01, 02, 03 or 04 CRC 2 Bytes Example Here is an example of a request/response to write the value "0001" to register 6000 (1770h): Request Response Write Multiple Registers (FC16) With this function code one or more 16-bit values can be written. This function can be used with the NanoJ objects (see "NanoJ Objects") or process data objects (see Process data objects (PDO) for details). Request ("N" being the number of registers to write) Name Length Value Slave Address 1 Byte Function code 1 Byte 10h Starting Address 2 Bytes 0000h to FFFFh Quantity of Registers 2 Bytes 0001h to 007Bh Byte Count 1 Byte 2 * N Registers Value N * 2 Bytes CRC 2 Bytes Response Name Length Value Slave Address 1 Byte Function code 1 Byte 10h Starting Address 2 Bytes 0000h to FFFFh Quantity of Registers 2 Bytes 0001h to 007Bh CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 90h Exception code 1 Byte 01, 02, 03 or 04 CRC 2 Bytes Example Here is an example of a request to write the values "0102h" and "0304h" starting at the register 6000 (1770h), number of registers is 2, length of the data 4: Request Response Report server ID (FC17) With this function code the description of the type, status and other information of the device can be read. Request Name Length Value Slave Address 1 Byte Function code 1 Byte 11h CRC 2 Bytes Response Name Length Value Slave Address 1 Byte Function code 1 Byte 03h Byte count 1 Byte 01h Run Indicator Status 1 Byte 00h = OFF, FFh = ON Additional Data CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 91h Exception code 1 Byte 01 or 04 CRC 2 Bytes Example Here is an example of a request and response to report the ID and status: Request Response Read/Write Multiple registers (FC23) With this function code one or more 16-bit values can be read and written at the same time. This function can be used with the NanoJ objects (see "NanoJ Objects") or process data objects (see Process data objects (PDO) for details). Request ("N" being the number of registers to write) Name Length Value Slave Address 1 Byte Function code 1 Byte 17h Read Starting Address 2 Bytes 0000h to FFFFh Quantity to Read 2 Bytes 0001h to 0079h Write Starting Address 2 Bytes 0000h to FFFFh Quantity to Write 2 Bytes 0001h to 0079h Write Byte Count 1 Byte 2 * N Write Registers Value N * 2 Bytes CRC 2 Bytes Response ("M" being the number of registers to write) Name Length Value Slave Address 1 Byte Function code 1 Byte 17h Byte count 1 Byte 2 * M Read Registers value M * 2 Bytes CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 97h Exception code 1 Byte 01, 02, 03 or 04 CRC 2 Bytes Example Here is an example of a request to read six registers starting at register 4, and to write three registers starting at register 15: Here is an example of a request to read two registers starting at 5000 (1388h) and a write to two registers at 6000 (1770h) with 4 bytes and the data "0102h" and "0304h": Request Response
Reading Input Registers / Read Holding Registers (FC03 / FC04) With this function code one or more 16-bit values can be read. This function can be used with the NanoJ objects (see "NanoJ Objects") or process data objects (minimum 4 byte alignment, see Process data objects (PDO) for details). Request Name Length Value Slave Address 1 Byte Function code 1 Byte 03h Starting Address 2 Bytes 0000h to FFFFh Quantity of Registers 2 Bytes 1 to 7Dh (125d) CRC 2 Bytes Response ("M" being the number of registers to read) Name Length Value Slave Address 1 Byte Function code 1 Byte 03h Byte count 1 Byte 2 * M Register value 2 Bytes CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 83h Exception code 1 Byte 01, 02, 03 or 04 CRC 2 Bytes Example Here is an example of a request to read register 5000 (1388h) and the following register (=2 registers): Request Response
Write Single Register (FC06) With this function code one 16-bit value can be written. This function can be used with the PDO area (see Process data objects (PDO)). Request Name Length Value Slave Address 1 Byte Function code 1 Byte 06h Register Address 2 Bytes 0000h to FFFFh Register Value 2 Bytes 0000h to FFFFh CRC 2 Bytes Response Name Length Value Slave Address 1 Byte Function code 1 Byte 06h Register Address 2 Bytes 0000h to FFFFh Register Value 2 Bytes 0000h to FFFFh CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 86h Exception code 1 Byte 01, 02, 03 or 04 CRC 2 Bytes Example Here is an example of a request/response to write the value "0001" to register 6000 (1770h): Request Response
Write Multiple Registers (FC16) With this function code one or more 16-bit values can be written. This function can be used with the NanoJ objects (see "NanoJ Objects") or process data objects (see Process data objects (PDO) for details). Request ("N" being the number of registers to write) Name Length Value Slave Address 1 Byte Function code 1 Byte 10h Starting Address 2 Bytes 0000h to FFFFh Quantity of Registers 2 Bytes 0001h to 007Bh Byte Count 1 Byte 2 * N Registers Value N * 2 Bytes CRC 2 Bytes Response Name Length Value Slave Address 1 Byte Function code 1 Byte 10h Starting Address 2 Bytes 0000h to FFFFh Quantity of Registers 2 Bytes 0001h to 007Bh CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 90h Exception code 1 Byte 01, 02, 03 or 04 CRC 2 Bytes Example Here is an example of a request to write the values "0102h" and "0304h" starting at the register 6000 (1770h), number of registers is 2, length of the data 4: Request Response
Report server ID (FC17) With this function code the description of the type, status and other information of the device can be read. Request Name Length Value Slave Address 1 Byte Function code 1 Byte 11h CRC 2 Bytes Response Name Length Value Slave Address 1 Byte Function code 1 Byte 03h Byte count 1 Byte 01h Run Indicator Status 1 Byte 00h = OFF, FFh = ON Additional Data CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 91h Exception code 1 Byte 01 or 04 CRC 2 Bytes Example Here is an example of a request and response to report the ID and status: Request Response
Read/Write Multiple registers (FC23) With this function code one or more 16-bit values can be read and written at the same time. This function can be used with the NanoJ objects (see "NanoJ Objects") or process data objects (see Process data objects (PDO) for details). Request ("N" being the number of registers to write) Name Length Value Slave Address 1 Byte Function code 1 Byte 17h Read Starting Address 2 Bytes 0000h to FFFFh Quantity to Read 2 Bytes 0001h to 0079h Write Starting Address 2 Bytes 0000h to FFFFh Quantity to Write 2 Bytes 0001h to 0079h Write Byte Count 1 Byte 2 * N Write Registers Value N * 2 Bytes CRC 2 Bytes Response ("M" being the number of registers to write) Name Length Value Slave Address 1 Byte Function code 1 Byte 17h Byte count 1 Byte 2 * M Read Registers value M * 2 Bytes CRC 2 Bytes Error Name Length Value Slave Address 1 Byte Error code 1 Byte 97h Exception code 1 Byte 01, 02, 03 or 04 CRC 2 Bytes Example Here is an example of a request to read six registers starting at register 4, and to write three registers starting at register 15: Here is an example of a request to read two registers starting at 5000 (1388h) and a write to two registers at 6000 (1770h) with 4 bytes and the data "0102h" and "0304h": Request Response
