M-Bus (Meter Bus, EN 13757) is a European standard for reading utility meters (water gas heat electricity) using a 2-wire bus that can power slave meters while transmitting consumption data.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | M-Bus+ | M-Bus data and power positive 36V | PWR |
| 2 | M-Bus- | M-Bus data and power negative | GND |