 |
| English | German |
| Euronet Switching Protocol 20 | ESP 20 |
| interfaces up to 20 kb/s and NRZ signalling | RS232 (0 = +3 to 25 V, 1 = -3 to -25V, adopted in CCITT Recommendations V.24, V.28 and DIN 66020, Tables V and IX) |
| RS232 interface with 20mA current loop | RS232A |
| series D20P-A DTAG modem | Apothekermodem (appr. 15000 sold to German pharmacies (1987 status)) |
| 500/20 signaling | 500/20 Hz-Ruf |
| 500/20 signalling | 500/20 Hz-Ruf |