FC 300 Design Guide
How to Program
Telegram timing
The communication speed between a master
and a slave depends on the baud rate. The
adjustable frequency drive’s baud rate must be
the same as the master ’s baud rate (selected
in par. 8-32 FC Port Baud Rate).
After a response teleg ram from the slave, make sure there is a pause of at least 2 characters (22
bits) before the master sends a new t elegram. At a b aud rate of 9600 baud, make sure there is a
pause of at least 2.3 ms. When the m aster has completed the telegram, the slave’s response time
to the master is maximum of 20 ms. There is a pause of at least 2 characters.
• Pause time, min: 2 characters
• Response time, min: 2 characters
• Response time, max: 20 ms
The time between the individual characters in
a telegram may not exceed 2 characters, and
thetelegrammustbecompletedwithin1.5x
nominal telegram time. At a baud rate of 9600
baud and a telegram length of 16 bytes, the
telegram is completed afte r 27.5 ms.
Telegr
am length (LGE)
The telegram length is the numb er of data bytes plus the address byte ADR and the data control byte BCC.
Thelengthoftelegramswith4databytesis: LGE=4+1+1=6bytes
The length of telegrams with 12 data bytes is: LGE = 12 + 1 + 1 = 14 bytes
The leng
th of telegrams containing t exts is 10+n bytes. 10 represents the fixed characters,
while the "n" is variable (depending on the length of the text).
A
djustable frequency d rive address (ADR)
Two different addres s formats are used. The adjustable frequency drive’s ad dre ss range is either 1-31 or 1-126.
1. Address format 1-31
Thebyteforaddressrange1-31has
the shown profile:
Bit 7 = 0 (address format 1-3 1 active)
Bit6isnotused
Bit 5 = 1: Broadcast, address bits (0-4) are not u se d
Bit 5 = 0: No Broadcast
Bit 0-4 = Adjustable frequency drive address 1-31
*
default setting ()display text []value for use in communication via serial communication port
270
MG.33.B
6.22 - V LT is a registered Danfoss trademark
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