Danfoss VLT AutomationDrive FC 301 Series Design Manual page 193

RS-485 Installation and Set...
12.7.3 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
Messagescontaining texts
Table 12.3 Length of Messages
1)
The 10 represents the fixed characters, while the "n'" is variable
(depending on the length of the text).
12.7.4 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.
1. 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
2. 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 follower returns the address byte unchanged to the
master in the response message.
12.7.5 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.
MG33BF22
Design Guide
LGE=4+1+1=6 bytes
LGE=12+1+1=14 bytes
1)
10 +n bytes
Rev. 2014-04-04 All rights reserved.
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