What is the RS232 pin configuration of the measuring device?
As with most serial interfaces, the serial port of Sourcetronic measuring devices is not entirely based on the RS-232 standard. Only the smallest subset of this standard is used, as shown in the table below:
| Signal | Code | Pin number |
| Transmitted data | TXD | 2 |
| Received data | RXD | 3 |
| Ground | GND | 5 |
This is clearly visible in the example of the milliohmmeter ST2515:
