Process Words (Pcd); Examples - Danfoss VLT AutomationDrive FC 360 Design Manual

RS485 Installation and Set-...
Conversion index
74
2
1
0
-1
-2
-3
-4
-5
Table 5.9 Conversion

5.4.13 Process Words (PCD)

The block of process words is divided into 2 blocks of 16
bits, which always occur in the defined sequence.
PCD 1
Control telegram (master⇒follower control
word)
Control telegram (follower⇒master) status
word
Table 5.10 Process Words (PCD)

5.5 Examples

5.5.1 Writing a Parameter Value
Change 4-14 Motor Speed High Limit [Hz] to 100 Hz.
Write the data in EEPROM.
PKE=E19E hex - Write single word in 4-14 Motor Speed High
Limit [Hz]:
•
IND=0000 hex.
•
PWEHIGH=0000 hex.
•
PWELOW=03E8 hex.
Data value 1000, corresponding to 100 Hz, see
chapter 5.4.12 Conversion.
The telegram looks like Illustration 5.9.
E19E H 0000 H 0000
PKE IND PWE
Illustration 5.9 Telegram
MG06B402
Design Guide
Conversion factor
3600
100
10
1
0.1
0.01
0.001
0.0001
0.00001
PCD 2
Reference-value
Present output
frequency
H 03E8 H
PWE
high low
Danfoss A/S © 09/2014 All rights reserved.
NOTICE
4-14 Motor Speed High Limit [Hz] is a single word, and the
parameter command for write in EEPROM is E.
4-14 Motor Speed High Limit [Hz] is 19E in hexadecimal.
The response from the slave to the master is shown in
Illustration 5.10.
119E H 0000 H 0000
IND PWE
PKE
Illustration 5.10 Response from Master
5.5.2 Reading a Parameter Value
Read the value in 3-41 Ramp 1 Ramp Up Time
PKE=1155 hex - Read parameter value in 3-41 Ramp 1
Ramp Up Time:
•
IND=0000 hex.
•
PWE =0000 hex.
HIGH
•
PWE =0000 hex.
LOW
1155 H 0000 H 0000
PKE IND
Illustration 5.11 Telegram
If the value in 3-41 Ramp 1 Ramp Up Time is 10 s, the
response from the slave to the master is shown in
Illustration 5.12.
1155 H 0000 H 0000
PKE
IND
Illustration 5.12 Response
3E8 hex corresponds to 1000 decimal. The conversion
index for 3-41 Ramp 1 Ramp Up Time is -2, that is, 0.01.
3-41 Ramp 1 Ramp Up Time is of the type Unsigned 32.
H 03E8 H
PWE
high low
H 0000 H
PWE PWE
high low
H 03E8 H
PWE PWE
high low
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