Introduction
The Standard Drive Interface is an electrical interface for roller shutter and
blind drives for the transmission of telegrams. In the following description of the
SMI interface, you will find essential technical data describing the principle of the system
.
The SMI Interface
The Interface Concept
| Interface Concept | one controller, several drives |
| Number of drives per controller | maximum 16 |
| Connection cables, number of cores | 5, incl. mains supply and PE |
| Connection cables, cable type | Installation cable, without shielding |
| Connection cables, maximum total cable length | 350 m |
| Connection cables, connection topology | no |
| Destruction of the drive interface in case of incorrect connection | no |
| Overvoltage resistance of the SMI input circuitry | 230VAC, 2kV surge test |
Communication
| Transmission rate | 2400 bit/s |
| Data transmission | bidirectional |
| Data protocol for uniform and manufacturer-specific commands | yes |
| Parallel operation of all drives without addressing | yes, with limited feedback |
| Individual operation with addressing | yes |
| Diagnostic response in parallel operation without addressing | yes |
Commissioning
The commissioning of drives is always manufacturer-dependent.
Data format and commands
| Data format with flexible length | yes |
| Data transmission security | Checksum verification |
| Synchronization mechanism | Handshake with timeout |
| Command types | uniform and manufacturer-specific |
| Addressing | Broadcast, group and individual addressing |
| Query of manufacturer code (M-ID) | yes |
| Query of serial number (Key-ID) | yes |
| Query of Key-ID for drives connected in parallel | yes, by means of a search procedure |
| Individual addressing | 16 drives |
| Uniform travel commands to end positions and stop | yes |
| Arbitrary positioning | yes, relative position, 16-bit, absolute position specification or query possible |
| Querying the position | yes, relative position, 16-bit, absolute position specification or query possible |
| Number of presettable fixed positions | 2 |
| Programming of fixed positions | yes, via standard commands |
| Query of fixed positions | yes, via standard commands |
| Incremental, absolute travel commands | yes, reference to rotation angle |
| Number of combinable travel commands | 3 for independent sequential processing |
| Drive parameters | Reading/writing of 1-, 2- and 4-byte parameters |
| Diagnostic response in parallel operation | yes, even without addressing the drives |
| Uniform diagnostic responses | Drive rotating, direction of rotation, drive error |
| Query of diagnostic responses during rotation | yes |
SMI test adapter
| Test adapter for drives and controllers available | yes |
| Power supply of the drive via test adapter | yes |
| Interface to test adapter | USB |
| Analysis with uniform software | yes, with SMI-easyMonitor software |