Differences between CAN- & NOVA-Bus
The NOVA-Bus is deliberately restricted to a subset of the features the CAN-Bus offers.
| CAN | NOVA 1.0 | NOVA5 |
|---|---|---|
| normal & extended frame format | only extended frame format | only extended frame format |
| remote frames | -- | -- |
| -- | 42 Volt line (0.1 Ampere) | -- |
| -- | 5 Volt line (1 Ampere) | 5 Volt line (1 Ampere) |
| send single message to multiple devices | single message for single device | single message for single device |
| -- | predefined identifier (29bit) | predefined identifier (29bit) |
| CAN FD | -- | -- |
| higher layers implementation (CANopen) | -- | -- |
| flexible bit rate | bit rate of 1MBit | bit rate of 1MBit |
| D-sub connector | RJ45 or Erni Minibridge P8 1.27 | Erni MiniBridge P4 1.27 |
| wire length depends on bit rate | up to 1.5m wire length | up to 1.5m wire length |
| -- | Broadcast messages | Broadcast messages |
| -- | command & respond | command & respond |
| -- | 8-wire ribbon cable or patch cable (AWG26) | 4-wire ribbon cable |
The NOVA-Bus uses a predefined identifier scheme, in which the ID is divided into various parts. The device ID is a number that defines the type of device, the Device EEPROM ID make it possible to use more than one device of the same type. The Device EEPROM ID is programable by the user. The Command ID is a number which represents a function of the device together with the 8 byte data block.
CAN 29bit identifier
| Bits | Range | ||
|---|---|---|---|
| 28 | 4096 ... 8191 | Device ID | NOVA-Controller |
| 27 ... 16 | 0 ... 4095 | Device ID | NOVA-Server (Device ID = 4095) NOVA-Devices |
| 15 ... 8 | 0 ... 255 | Device EEPROM ID | |
| 7 ... 0 | 0 ... 255 | Command ID |
Special Device IDs
| Device ID | Device type | |
|---|---|---|
| 4096 | NOVA-Controller (NC6,NC2) | maintenance & monitoring |
| 4095 | NOVA-Stack | Software |
| 1011 | NDS40 | Piezo Servo Positioner |
| 1012 | NDS70 | Piezo Positioner |
| 1013 | NDES1 | Piezo Servo Controller |
| 1014 | NDEM3 | Piezo Controller |
| 1016 | NDMS1 | Multiphase Piezo Servo Controller |