MG.90.D1.02 – VLT is a registered Danfoss trademark
26
VLT
®
5000/5000 Flux/6000 HVAC/8000 AQUA PROFIBUS
■
Example 2: Process data from the VLT
Example for filling the variable process data in
PPO 4.
Assumption: the VLT is operating as in the previous
example. At the same time, the motor current
(PCD1), the status of the digital inputs (PCD2), the
frequency value in Hz (PCD3), and the voltage at
terminal 53 (PCD4) are to be indicated.
Fixing the process data on the display unit
The process data from the VLT are read. Therefore,
the parameter 916 (PCD-Read) must be used for
the configuration of the PCD.
A) The parameter number for displaying the motor
current is entered on the display unit of the VLT
under the index number <1>: 520.
B) The parameter number for displaying the digital
inputs is entered under the index number <2>:
528.
C) Index number <3> = 518 (display of the fre-
quency)
D) Index number <4> = 529 (display of the voltage
at input 53)
VLT response PPO type 4
For example, the VLT response of a PPO 4 tele-
gram after the configuration might look like this:
Byte
Value (Hex)
STW
1 and 2
0F07
MAV
3 and 4
2000
PCD
PCD1
5 and 6
00F6
PCD2
7 and 8
0028
PCD3
9 and 10
00FA
PCD4 11 and 12
02F8
STW
0F07Hex means that the motor is running and that
no warnings or errors are present (further details
can be found in the status word table).
MAV
2000Hex indicates that the output frequency is
50% of the maximum frequency.
PCD1
HEX F6 = 246 decimal. The conversion index for
parameter 520 is -2, i.e. the value must be divided
by 100. Thus, the present motor current is: 2.46 A
PCD2
Hex 28 = 0010 1000 binary. The allocation of the
digits:
16 17 18 19 27 29 32 32 (digital inputs of the VLT)
This means that input 18 and input 27 of the VLT
are switched.
PCD 3
Hex FA = 250 decimal. The conversion index for
parameter 518 is -1, i.e. the value must be divided
by 10. Thus, the instantaneous frequency is 25.0 Hz.
PCD4
Hex 2F8 = 760 decimal. The conversion index for
parameter 529 is -2, i.e. the value must be divided
by 100. Thus, the instantaneous voltage at terminal
53 of the VLT is: 7.60 Volt.
Information concerning the conversion index
for each parameter can be found in the
parameter list.
The explanation of the column headings for the
parameter table can be found in the section ”Para-
meter and data structures” (keyword: size
attribute).
Examples
