All values are transmitted in non human readable form as bytes. This format is preferred as it is the most efficient because it uses a minimal amount of data per message.
Each message has the same format and only differs in length based on the amount of data points transmitted per message.
| Name | Length [Byte] | Description |
|---|---|---|
| HDR | 5 | Message header with CNT=0bXXXX00XX |
| ID0 | 1 | ID of first value |
| VAL0 | 4 | First value |
| ID1 | 1 | ID of second value |
| VAL1 | 4 | Second value |
| ... | ... | ... |
| CS | 1 | Message checksum byte |
Total message length: 5 + PLL + 1
| Name | Length [Byte] | Description |
|---|---|---|
| HDR | 5 | Message header with CNT=0bXXXX10XX |
| ID | 1 | ID |
| VAL0 | 4 | First value |
| VAL1 | 4 | Second value |
| ... | ... | ... |
| VALn | 4 | Last value |
| CS | 1 | Message checksum byte |
Total message length: 5 + PLL + 1 where PLL is the number of payload bytes including the ID byte
| Name | Length [Byte] | Description |
|---|---|---|
| HDR | 5 | Message header with CNT=0bXXXX01XX |
| CH0 | 1 | First char |
| CH1 | 1 | Second char |
| ... | ... | ... |
| CHN | 1 | Last char |
| CS | 1 | Message checksum bytes |
Total message length: 5 + PLL + 1 where PLL is the string length.
The header consists of the following 5 bytes
| Name | Length [Byte] | Description |
|---|---|---|
| SIG | 1 | Signature byte for message and receiver identification |
| CNT | 1 | Control byte for configuration flags |
| PLL | 2 | Number of payload bytes transmitted in this message |
| HCS | 1 | Header checksum |
The signature byte is used by the receiver to identify the sender and is 0xFF by default.
The control byte contains flags for configuration.
| Bit | Function | Options | Remarks |
|---|---|---|---|
| CNT[7] | Data Byte Order | 0 = MSB first, 1 = LSB first | Byte order is the same as sender endianess if SPARQS libraries are used |
| CNT[6] | Checksum Type | 0 = NONE, 1 = XOR8 | Only applies to the payload checksum, header checksum is always XOR8 |
| CNT[5] | reserved | - | |
| CNT[4] | reserved | - | |
| CNT[3:2] | Message Type | 00 = value/id pair, 01 = string, 10=bulk single id | |
| CNT[1] | Data Sign | 0 = unsigned, 1 = signed | Ignored if type is float or string |
| CNT[0] | Data Type | 0 = float, 1 = integer | Ignored if type is string |
Contains the total number of payload bytes transmitted.
Contains the value as float, uint32 or int32 and its ID.
XOR8 checksum byte or undefined when message checksum is turned off. Header checksum cannot be turned off.