Communication between Delta PLC and Danfoss VLT6000 Series Adjustable VFD

Communication between Delta PLC
and Danfoss VLT6000 Series Adjustable VFD

Control Purpose:


  • Controlling the start/stop status and reading
    out the frequency of Danfoss VLT6000 series frequency drive through
    communication by master PLC.

Parameter Settings for VLT6000 Series frequency
drive:

Parameter
Set
value
Explanation
P500
0
FC protocol : Serial communication protocol
P501
1
FC communication address: 1
P502
5
FC communication baud rate: 9600 bps
P503
1
Coasting stop controlled by serial communication
P504
1
DC braking controlled by serial communication
P505
1
Start controlled by serial communication
  •         If Danfoss VLT6000 frequency inverter cannot run
    normally due to improper parameters, users can set VLT6000 to factory defaults:
    set P620 = 3 and press OK. Then set the parameters according to the above
    table.

Devices:

DEVICE
Function
X0
Start/stop switch
M0
Executing the 1st RS instruction
M1
Executing the 2nd RS instruction
Control Program:

 


·       
Program
Description:

  •         Initialize
    PLC RS-485 communication port and set the communication format as, 9600, 8, E, 1.
    The RS-485 communication format of VLT6000 should be the same with Master PLC.
  •         When X0
    = ON, VLT6000 starts to run forward in 40Hz and its output frequency will be
    read out.

PLC =>
VLT6000, PLC sends: 02 0E 01 1200 0000 00000000 047F 2000 44
VLT6000 =>PLC, PLC receives: 02 0E 01 1200 0000 000000FA 0F07 1FFF 0D
Register
for sent data (PLC sends out messages):
Register
Data
Explanation
D100 low
02H
Head, fixed as 02H (start of the message)
D100 high
0EH
The number of the following bytes
D101 low
01H
Station No. (range: 0~31, corresponding to hex 00H~1FH)
D101 high
12H
PKE
1H: function code for reading parameters
200H: parameter No. P512 (output
frequency)
PKW area
D102 low
00H
D102 high
00H
IND
Index area (used in indexed parameters,
such as P615. Not used in this program.)
D103 low
00H
D103 high
00H
PWE high
Value: 1 (In read status: 0. In write status:
high word will be read)
D104 low
00H
D104 high
00H
PWE low
Value: 2 (In read status: 0. In write status:
low word will be read)
D105 low
00H
D105 high
04H
PCD1 area
Control word (starting VLT6000. For the definition,
please refer to Remarks.)
D106 low
7FH
D106 high
20H
PCD2 area
Frequency (4000H corresponds to base frequency
50Hz and 2000H corresponds to 25Hz)
D107 low
00H
D107 high
44H
BCC area
Tail. (XOR result of all the bytes before this byte)
Register
for received data (VLT6000 responds with messages):
Register
Data
Explanation
D120 low
02H
Head, fixed as 02H (start of the message)
D120 high
0EH
The number of the following bytes
D121 low
01H
Station No. (range: 0~31, corresponding to hex 00H~1FH)
D121 high
12H
PKE
1H: function code for reading parameters
200H: parameter No. P512 (output
frequency)
PKW area
D122 low
00H
D122 high
00H
IND
Index area (used in indexed parameters,
such as P615. This program doesn’t use.)
D123 low
00H
D123 high
00H
PWEhigh
High word will be read
D124 low
00H
D124 high
00H
PWElow
Low word will be read (00FAH
corresponds to the decimal value 250
which means the frequency of 25Hz.
D125 low
FAH
D125 high
0FH
PCD1 area
Status word (For the definition, please refer to
Remarks.)
D126 low
07H
D126 high
1FH
PCD2 area
Frequency (4000H corresponds to the base
frequency 50Hz and 1FFFHZ corresponds to 25Hz)
D127 low
FFH
D127 high
0DH
BCC area
Tail. (XOR result of all the bytes before this byte)
When X0 = OFF, AC motor drive will stop. (Only
PCD area is applied in this message).

PLC => VLT6000, PLC sends: 02 06 01
0477 0000 76
VLT6000 => PLC, PLC receives: 02 06 01 0603 0000 00
Register for sent data (PLC
sends out messages):
Register
Data
Explanation
D200 low
02H
Head, fixed as 02H (start of the message)
D200 high
06H
The number of the following bytes
D201 low
01H
Station No. (range: 0~31, corresponding to hex 00H~1FH)
D201 high
04H
Control byte (starting AC motor drive. For the definition,
please refer to Remarks.)
D202 low
77H
D202 high
00H
Frequency (0000H corresponding to 0Hz)
D203 low
00H
D203 high
76H
Tail. (XOR result of all the bytes before this byte)
Register
for received data (VLT6000 responds with messages):
Register
Data
Explanation
D220 low
02H
Head, fixed as 02H (start of the message)
D220 high
06H
The number of the following bytes
D221 low
01H
Station No. (range: 0~31, corresponding to hex 00H~1FH)
D221 high
06H
Status byte (starting AC motor drive. For the definition, please
refer to Remarks.)
D222 low
03H
D222 high
00H
Frequency (0000H corresponding to 0Hz)
D223 low
00H
D223 high
00H
Tail. (XOR result of all the bytes before this byte)
·       
There are 2 situations for
RS communication: M1123 for normal communication and M1129 for receiving
timeout. When communication time-out occurred, M2 can be used to retry.

Remarks:

·       
There are 3 protocols for
Danfoss VLT6000 series inverter: FC (default), Metasys N2 and LS FLN. This
program uses FC protocol which is similar with USS protocol used by Siemens MM420
series inverter: allows maximum of one master connected with 31 slaves. Slave
ID: 0~31.
Image




·       
The definitions of STX, LGE, ADR and BCC areas of FC protocol are
the same as that of

·       
3 kinds of messages can be used in data area:



o  
Definition of the control word for AC motor drive in PZD area:
Bit
Bit status = 0
Bit status = 1
00
Preset ref. lsb
01
Preset ref. msb
02
DC braking
03
Coasting stop
04
Quick stop
05
Freeze output frequency
06
Ramp stop
Start
07
Reset
08
JOG
09
No function
10
Data not invalid
Data valid
11
Activate relay 01
12
Activate relay 02
13
Choice of setup lsb
14
Choice of setup msb
15
Reversing
Definition
of the status word for AC motor drive in PCD area
Bit
Bit status = 0
Bit status = 1
00
Trip
Control ready
01
Drive ready
02
Stand by
03
No trip
Trip
04
Not in use
05
Not in use
06
Not in use
07
No warning
Warning
08
Speedreference
Speed = reference
09
Local operation
Serial comm. control
10
Out of frequency range
11
Disable operation
Operation indication
12
No function
13
Voltage warning high/low
14
Current limit
15
Thermal warning

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