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In order to increase the data safety, a check sum is transmitted.
The check sum is the 1 byte sum of all hex values from the start character to the last
character in front of the check sum.
Example: The Master sends :
„
[M01V07C6\r
„
ASCII Hex
Meaning
1.Byte
[
5Bh
Start signal
2.Byte
M
4Dh
Transmitter identification
M= Master
3.Byte
0
30h
Slave address
4.Byte
1
31h
Slave address
5.Byte
V
56h
Identifier data group
6.Byte
0
30h
Length of the data field (0)
7.Byte
7
37h
Length of the data field (7)
8.Byte
C
43h
Check
sum
9.Byte
6
36h
Check
sum
10.Byte
\r
0Dh
End-character
CR
A checksum is built up from the bytes in the data field.
5Bh+4Dh+30h+31h+56h+30h+37h = 1C6h--> 1 Byte Summe = C6h
In order to be able to query variables without changes, it is possible to set the „*“
character instead of a variable in the master command. The receiver, thus the
thermostat, will not change the variable at this position. In this case,
all positions
which
the variable takes, have to be rendered with the „*“ character. In the examples, the
thermostat is always addressed with the identifier (device address) 01.
´V´ Verify - Command
Provided to check the presence of a slave.
Master query:
„[M01V07C6\r“
The master queries whether the slave 01 is connected to the bus.
Slave answer:
„[S01V0EMINI CCAD\r“
Slave 01 (temperature control device) is connected. The device
is a MINI CC (Example). The slave command has the „MINI CC“ data group, which is 7
bytes long. These 7 bytes plus the 7 bytes in front of the data group produce a data
field length of 14 bytes = 0Eh byte.
