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 r esp onse telegram from the slave, make sure t here is a pause of at least 2 characters (22
bits) before the master sends a new telegram. At a baud rate of 9600 baud, make sure there is a
pause of at least 2.3 ms. When the master has completed the telegram, the slave’s re sponse 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 betwee n 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 after 27.5 ms.
Telegr
am length ( LGE)
The telegram length is the number of data bytes plus the address b yte 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 frequ ency dr i ve address (ADR)
Two different address formats are used. The adjustable freque n cy drive’s address range is ei ther 1-31 or 1-126.
1. Addre s s forma t 1-31
Thebyteforaddressrange1-31has
the shown profile:
Bit 7 = 0 (addre ss format 1-31 active)
Bit6isnotused
Bit 5 = 1: Broadca st, a dd ress bits (0-4) are not used
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 c ommunication port
236
MG.33.B
3.22 - VLT is a registered Danfoss trademark
To Next Page
Loading...
Need help?
General