The TeleFlash instruments are interfaced via RS232 cabling. Below is a pin to pin diagram of the standard cable which is supplied with the instrument.
| DB9s (female) | DB25p (male) |
| 2 | 2 |
| 3 | 3 |
| 5 | 7 |
| 6 & 8 | 6 & 8 & 20 |
| 4 & 5 |
Note that there are four jumpers; one inside the DB9s and three within the DB25p. It appears that the jumpers serve to completly disable hardware handshake.