1.4.1 Host Interface Description
Meters And More Host Interface is a Serialization Protocol, which is defined by the Meters And More Standard, and is required to perform a Certification.
This Certification requirement is the reason why the Embedded part of this Serialization Protocol is provided along with the Meters And More Stack.
Host Interface duties are to transport commands from a Serial Interface to the Meters And More Stack, and vice versa.
Commands and Codes
Host Interface provides different functionalities based on different commands.
Commands are specified according to the following table:
| CMD Name | REQUEST | Positive CONFIRM | Negative CONFIRM | INDICATION | Description |
|---|---|---|---|---|---|
| BIO_Reset | 0x3C | 0x3D | - | 0x3E | Allows the Host Controller to reset the Meters And More Device (REQ) and be informed of when the reset is completed (IND) |
| MIB_Write | 0x08 | 0x09 | 0x0B | 0x0A | Writes an object on Information Base |
| MIB_Read | 0x0C | 0x0D | 0x0F | - | Reads an object from Information Base |
| Slave_Data | 0x24 | 0x25 | 0x27 | 0x26 | Send response messages to a Master Data Request over PLC behaving as a Slave node |
| Master_Data | 0x28 | 0x29 | 0x2B | 0x2A | Send messages over PLC while behaving as a Master node |
| HI_Ping | 0x2C | 0x2D | - | - | Performs a “ping” on the Host Interface. CFM uses the same payload as the REQ command |
| HI_Error | - | - | - | 0x36 | Received command frame is not recognized as a valid request command code |
In addition to the standard ones, Microchip implementation adds a new command for
sending frames at PHY level:
| CMD Name | REQUEST | Positive CONFIRM | Negative CONFIRM | INDICATION | Description |
|---|---|---|---|---|---|
| Phy_Data | 0x48 | 0x49 | 0x4B | 0x4A | Sends a frame over PLC PHY |
When a Negative CONFIRM is received, the possible Error Codes are the
following:
| Error Code | Value | Description |
|---|---|---|
| WPL | 0x02 | Wrong argument/parameter length |
| WPV | 0x03 | Wrong argument/parameter value |
| BUSY | 0x04 | Function is busy or not configured |
| NOT_PRESENT | 0x06 | Function is physically not present or not connected |
| DISABLED | 0x07 | Function is disabled by a software option |
| TIMEOUT | 0x08 | Operation timeout |
| ERROR | 0xFF | Generic error |
The BIO_Reset Indication command returns one byte of information, encoded in the
following way:
| Byte Index | bit 7 | bits 6 to 0 |
|---|---|---|
| Reconfiguration Status | Reset Cause |
Reconfiguration Status:
- 0: One or more reconfigurable MIB objects has not been reconfigured
- 1: All reconfigurable MIB objects has been reconfigured
Reset Cause:
- 0: Power-on or HW reset
- 1: Watchdog reset
- 2: SW reset
- 3: BIO Request
- 4: Diagnostic: Inconsistent PLC PHY ISR received
- 5: Diagnostic: Timer and ZERO CROSSING
- 6: Diagnostic: FSM unreachable state
- 7: Diagnostic: No ISR from PLC