For interface control, some control characters from the ASCII code range of 0 to 20 hex are predefined and can be transmitted via the interface.
Control strings or control characters of the RS-232-C interface
| Control Character | Function |
| Break (at least 1 character only log 0) | Reset instrument |
| 0Dhex, 0Ahex | Terminator <CR>, <LF> Switchover between local/remote |