User Manual of EM760 High-Performance Inverter 10.3.3.5 0x06: function code used to write a single register or command In the remote terminal unit, this function code is used to write a single holding register. The request PDU describes the address to be written to the register. The normal response is the response made to the request, which is returned after the register content is written. ● Request PDU ● Response PDU ● Error PDU Below is an example of a request to change the drive control mode of the motor 1 (F00.01) to “1: SVC”. * The function code 0x06 cannot be used if modified frequently, in order to avoid damage to the inverter.
The user-defined function code 0x41 “change without saving” corresponds to the standard common function code 0x06. Its definition is the same as that ofthe corresponding standard function code (the same request, response and error PDU). The difference is that when the slave responds to this user-defined function code, the corresponding value of RAM is changed only and not stored in EEPROM (holding register). For the function codes (e.g. F00.07) that are often modified, it is recommended to use the function code 0x41 (you can change the main frequency source A by directly setting 7001H, as detailed in 10.3.4), to avoid damage to the inverter. The specific operation is as follows.
260 Function code 1 byte 0x06 Address of register 2 bytes 0x0000~0xFFFF Register value 2 bytes 0x0000~0xFFFF Function code 1 byte 0x06 Address of register 2 bytes 0x0000~0xFFFF Register value 2 bytes 0x0000~0xFFFF Error code 1 byte 0x86 Exception code 1 byte See Table 10-4 Request Respond Domain name (0x) Domain name (normal) (0x) Domain name (abnormal) (0x) Function 06 Function 06 Function 86 Register address Hi 00 Register address Hi 00 Exception code 03 Register address Lo 01 Register address Lo 01 Register value Hi 00 Register value Hi 00 Register value Lo 01 Register value Lo 01