====== 3.3 CMD_PD ======

This command exchanges the process data with the connected device. Process data is not validated in length or content.

**Command:**

^ Octet # ^ Usage ^
| 0 | Command ID = 0x03 |
| 1 | Port index 0x00 or 0x01 |
| 2 | Length Out |
| 3 | Length In |
| 4.. | Data Out |

The //**Length Out**// field command is length for the output process data. The structure and length of the output data can be found in the SDCI device’s documentation. The //**Length In**// field needs to be set according to the device’s documentation. If the length fields are not correctly set, this may lead to invalid data or loss of communication.

**Return Success:**

^ Octet # ^ Usage ^
| 0 | Command ID = 0x03 |
| 1 | Port index 0x00 or 0x01 |
| 2 | Length Out (as given in the command) |
| 3 | Length In (as given in the command) |
| 4.. | Data In |