Danfoss VLT AQUA Drive FC 202 Design Manual page 85

System Integration
A data control byte (BCC) completes the message.
STX LGE ADR
Figure 3.46 Message Structure
3.8.7.3 Message Length (LGE)
The message length is the number of data bytes plus the
address byte ADR and the data control byte BCC.
4 data bytes
12 data bytes
Messages containing texts
Table 3.27 Length of Messages
1) The 10 represents the fixed characters, while n is variable
(depending on the length of the text).
3.8.7.4 Adjustable Frequency Drive Address
(ADR)
Two different address formats are used.
The address range of the adjustable frequency drive is
either 1-31 or 1-126.
•
Address format 1-31
- Bit 7=0 (address format 1-31 active).
- Bit 6 is not used.
- Bit 5=1: Broadcast, address bits (0-4) are
not used.
- Bit 5=0: No Broadcast.
- Bit 0-4=adjustable frequency drive
address 1-31.
•
Address format 1-126
- Bit 7=1 (address format 1-126 active).
- Bit 0-6=adjustable frequency drive
address 1-126.
- Bit 0-6 =0 Broadcast.
The slave returns the address byte unchanged to the
master in the response message.
3.8.7.5 Data Control Byte (BCC)
The checksum is calculated as an XOR-function. Before the
first byte in the message is received, the calculated
checksum is 0.
MG20N622
Design Guide
DATA BCC
LGE=4+1+1=6 bytes
LGE=12+1+1=14 bytes
1)
10 +n bytes
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