medlab EG01010 - Page 18

Medlab medizinische Diagnosegeräte GmbH EG01010 User Manual
Version 1.06
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Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Byte 1
Sync
1 1 1 1 1 0 0 0
Byte 2
Ctr/Chk
Bit 3
Ctr
Bit 2
Ctr
Bit 1
Ctr
Bit 0
Ctr
Bit 3
Chksum
Bit 2
Chksum
Bit 1
Chksum
Bit 0
Chksum
Byte 3
Wave 1
Bit 7
Wave 1
Bit 6
Wave 1
Bit 5
Wave 1
Bit 4
Wave 1
Bit 3
Wave 1
Bit 2
Wave 1
Bit 1
Wave 1
Bit 0
Wave 1
Byte 4
Wave 2
Bit 7
Wave 2
Bit 6
Wave 2
Bit 5
Wave 2
Bit 4
Wave 2
Bit 3
Wave 2
Bit 2
Wave 2
Bit 1
Wave 2
Bit 0
Wave 2
........
2+Ctr bytes are transmitted in this block. Ctr is the number of wave samples in the block.
The checksum is the sum of all bytes in the block, with byte 2, the chksum itself, ignored for the sum. It
includes the sync character (byte 1). Since only 4 bits can be used, the result is "anded" with 0x0F.
The wave samples are limited to a number of 0xF7, so no mix-up with sync bytes can occur.
The channels are not mapped to a byte position in the block, since the user can freely enable/disable the
channels independently of each other.
The transmission sequence is always: I or II or III, Respiration
Example 1: the host requests „I“ and transmits „(0x43, 0x01)“. Wave 1 of the answer will be „I“, the block
being 3 bytes long.
Example 2: the host requests „III“ and „respiration“ and transmits „(0x43, 0x84)“.
Wave 1 will be „III“, wave 2 will be the respiration waveform, the answer block being 4 bytes long.
A value block contains three bytes:
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Byte 1
Sync
1 1 1 1 1 0
Bit 1
Type
Bit 0
Type
Byte 2
Chksum
0
Bit 6
Chksum
Bit 5
Chksum
Bit 4
Chksum
Bit 3
Chksum
Bit 2
Chksum
Bit 1
Chksum
Bit 0
Chksum
Byte 3
Value
Bit 7
Value
Bit 6
Value
Bit 5
Value
Bit 4
Value
Bit 3
Value
Bit 2
Value
Bit 1
Value
Bit 0
Value