> For the complete documentation index, see [llms.txt](https://inacks.gitbook.io/is4310-wiki/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://inacks.gitbook.io/is4310-wiki/datasheet/description/function-codes.md).

# Function Codes

Following Function Codes are available on the IS4310 (Modbus Slave):

* 0x03 - Read Holding Registers
* 0x06 - Write Sigle Register
* 0x10 - Write Multiple Registers

If the PLC (Modbus Master) attempts to execute a query with a Function Code not listed above, the IS4310 (Modbus Slave) will respond with Exception Code 1.