Process Words (Pcd); Examples; Writing A Parameter Value; Reading A Parameter Value - Danfoss VLT AutomationDrive FC 300 Design Manual

RS-485 Installation and Set...
4-12 Motor Speed Low Limit [Hz] has a conversion factor of
0.1.
To preset the minimum frequency to 10 Hz, transfer the
value 100. A conversion factor of 0.1 means that the value
transferred is multiplied by 0.1. The value 100 is thus
perceived as 10.0.

Examples:

0 s⇒conversion index 0
0.00 s⇒conversion index -2
0 ms⇒conversion index -3
0.00 ms⇒conversion index -5
Conversion index
100
75
74
67
6
5
4
3
2
1
0
-1
10 10
-2
-3
-4
-5
-6
-7
Table 10.7 Conversion Table

10.7.13 Process Words (PCD)

The block of process words is divided into two blocks of
16 bits, which always occur in the defined sequence.
Control Telegram (master⇒follower Control
word)
Control Telegram (follower⇒master) Status
word
Table 10.8 PCD Sequence
10.8 Examples

10.8.1 Writing a Parameter Value

Change 4-14 Motor Speed High Limit [Hz] to 100 Hz.
Write the data in EEPROM.
246
VLT
Conversion factor
1000000
100000
10000
1000
100
10
1
0.1
0.01
0.001
0.0001
0.00001
0.000001
0.0000001
PCD 1
Reference-value
Present output
frequency
®
AutomationDrive FC 300 Design Guide 90-1200 kW
PKE=E19E Hex - Write single word in 4-14 Motor Speed High
Limit [Hz]
IND=0000 Hex
PWE =0000 Hex
high
PWE =03E8 Hex - Data value 1,000, corresponding to 100
low
Hz, see10.7.12 Conversion.
E19E H
PKE
Illustration 10.11 Telegram
NOTICE
4-14 Motor Speed High Limit [Hz] is a single word, and the
parameter command for write in EEPROM is "E."
Parameter number 4–14 is 19E in hexadecimal.
119E
PKE
Illustration 10.12 Response from Master to Follower

10.8.2 Reading a Parameter Value

Read the value in 3-41 Ramp 1 Ramp Up Time
PKE=1,155 Hex - Read parameter value in 3-41 Ramp 1
Ramp Up Time
IND=0000 Hex
PWE =0000 Hex
high
PWE =0000 Hex
low
1155
PKE
Illustration 10.13 Parameter Value
PCD 2
If the value in 3-41 Ramp 1 Ramp Up Time is 10 s, the
response from the follower to the master is:
1155
PKE
Illustration 10.14 Response from Follower to Master
3E8 Hex corresponds to 1000 decimal. The conversion
index for 3-41 Ramp 1 Ramp Up Time is -2.
3-41 Ramp 1 Ramp Up Time is of the type Unsigned 32.
MG34S202 - Rev. 2013-08-19
0000 H 0000 H 03E8
IND PWE PWE
high
H 0000 H 0000 H 03E8
IND PWE
high
H 0000 H 0000 H 0000
IND PWE
high
H 0000 H 0000 H 03E8
PWE
IND
high
H
low
H
PWE
low
H
PWE
low
H
PWE
low