Kruger Ecowatt K320 Series Operation Manual page 292

Ecowatt Drive K320 series
®
START
ADDR (address)
CMD (command code)
Most significant byte (MSB) of the
start address
Least significant byte (LSB) of the
start address
MSB of data quantity
LSB of data quantity
LSB of CRC
MSB of CRC
END
"START" and "END" are "T1-T2-T3-T4 (time gap with a min. length of 3.5 bytes)", indicating
that a time gap with a minimum length of 3.5 bytes must be kept before RS485 communication
is executed. The time gap is used to distinguish one message from another so that the two
messages are not regarded as one message.
"ADDR" is "01H", indicating that the command is sent to the VFD whose address is 01H. The
ADDR information occupies one byte.
"CMD" is "03H", indicating that the command is used to read data from the VFD. The CMD
information occupies one byte.
"Start address" indicates that data reading is started from this address. It occupies two bytes,
with the high-order bit on the left and low-order bit on the right.
"Data count" indicates the count of data to be read (unit: word). "Start address" is "0004H" and
"Data count" is 0002H, indicating that data is to be read from the data addresses of 0004H and
0005H.
CRC check occupies two bytes, with the low-order bit on the left and high-order bit on the
right.
RTU slave response (sent from the VFD to the master):
START
ADDR
CMD
Number of bytes
MSB of data in 0004H
LSB of data in 0004H
MSB of data in 0005H
LSB of data in 0005H
LSB of CRC
MSB of CRC
END
T1-T2-T3-T4 (transmission time of 3.5 bytes)
T1-T2-T3-T4 (transmission time of 3.5 bytes)
T1-T2-T3-T4 (transmission time of 3.5 bytes)
T1-T2-T3-T4 (transmission time of 3.5 bytes)
-283-
Communication
01H
03H
00H
04H
00H
02H
85H
CAH
01H
03H
04H
13H
88H
00H
00H
7EH
9DH