The communicationprotocol between the ADC-box and the aquisitionsoftware.
-------------------------------------------------------------------------

RS-232 settings: 115K2, 8N1, no flowcontrol

The communication is oneway only, no bytes are transmitted from the pc to the ADC-box.
As soon as the ADC-box is switched on, it will transmit data, regardles a pc is connected or not.

The ADC-box transmits data in blocks of 9220 bytes: 12 channels * 3 bytes per channel * 256 Hz + 4 sync bytes

The order is:


|<--------------- 4 synchronisation bytes -------------->|
|                                                        |           (SYNC_END has decimal value 192,
|  SYNC_END   |  SYNC_END   | sequence nr. |  SYNC_END2  |            SYNC_END2 has decimal value 17)


|<------------------------------------------ sample 0 ---------------------------------------------------------->|
|                                                                                                                |
|<------- channel 0 ------>|<------- channel 1 ------>|<------- channel 2 ------>| ... |<------ channel 12 ----->|
|                          |                          |                          |     |                         |
| byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | ... |byte 0 | byte 1 | byte 2 |


|<------------------------------------------ sample 1 ---------------------------------------------------------->|
|                                                                                                                |
|<------- channel 0 ------>|<------ channel 1  ------>|<------- channel 2 ------>| ... |<------ channel 12 ----->|
|                          |                          |                          |     |                         |
| byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | ... |byte 0 | byte 1 | byte 2 |


|<------------------------------------------ sample 2 ---------------------------------------------------------->|
|                                                                                                                |
|<------- channel 0  ----->|<------- channel 1  ----->|<------- channel 2  ----->| ... |<------ channel 12 ----->|
|                          |                          |                          |     |                         |
| byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | ... |byte 0 | byte 1 | byte 2 |


                                             sample 3 ... 253


|<------------------------------------------ sample 254 -------------------------------------------------------->|
|                                                                                                                |
|<------- channel 0  ----->|<------- channel 1  ----->|<------- channel 2  ----->| ... |<------ channel 12 ----->|
|                          |                          |                          |     |                         |
| byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | ... |byte 0 | byte 1 | byte 2 |


|<------------------------------------------ sample 255 -------------------------------------------------------->|
|                                                                                                                |
|<------- channel 0  ----->|<------- channel 1  ----->|<------- channel 2  ----->| ... |<------ channel 12 ----->|
|                          |                          |                          |     |                         |
| byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | ... |byte 0 | byte 1 | byte 2 |



|<--------------- 4 synchronisation bytes -------------->|
|                                                        |
|  SYNC_END   |  SYNC_END   | sequence nr. |  SYNC_END2  |


|<------------------------------------------ sample 0 ---------------------------------------------------------->|
|                                                                                                                |
|<------- channel 0  ----->|<------- channel 1  ----->|<------- channel 2  ----->| ... |<------ channel 12 ----->|
|                          |                          |                          |     |                         |
| byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | ... |byte 0 | byte 1 | byte 2 |


|<------------------------------------------ sample 1 ---------------------------------------------------------->|
|                                                                                                                |
|<------- channel 0  ----->|<------- channel 1  ----->|<------- channel 2  ----->| ... |<------ channel 12 ----->|
|                          |                          |                          |     |                         |
| byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | ... |byte 0 | byte 1 | byte 2 |


|<------------------------------------------ sample 2 ---------------------------------------------------------->|
|                                                                                                                |
|<------- channel 0  ----->|<------- channel 1  ----->|<------- channel 2  ----->| ... |<------ channel 12 ----->|
|                          |                          |                          |     |                         |
| byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | byte 0 | byte 1 | byte 2 | ... |byte 0 | byte 1 | byte 2 |


etc.



SYNC_END  has decimal value 192
SYNC_END2  has decimal value 17
sequencenr. has a decimal value in the range 0 ... 255
After every block of data the sequence number will increase by one.


Description of a sample of one channel:


|<------------------- byte 0 -------------------------->|
|                                                       |
| DB21 | DB20 | DB19 | DB18 | DB17 | DB16 | DB15 | DB14 |
   |
  MSB


|<------------------- byte 1 -------------------------->|
|                                                       |
| DB13 | DB12 | DB11 | DB10 | DB9  | DB8  | DB7  | DB6  |



|<------------------- byte 2 -------------------------->|
|                                                       |
| DB5  | DB4  | DB3  | DB2  | DB1  | DB0  |  X   | o.f. |
                                      |      |      |
                                     LSB     |    overflow bit, is one during overflow
                                             |
                                           not used

ADC-data is two's complement.