Rockwell Automation 20-COMM-H RS485 HVAC Adapter FRN 2.xxx - Manual (Page 50)

5-4 Using Metasys N2
20-COMM-H RS-485 HVAC Adapter User Manual
Publication 20COMM-UM009D-EN-P
Reference Setup Examples
Table 5.G Example Speed Reference and Feedback for a PowerFlex 70/700 Drive
Reference
(1)
(1) The actual value transmitted over the network is an engineering unit where
100% equals sending the value in the adapter Parameter 29 - [N2 Ref Scale],
and 0% equals sending a zero.
Feedback
(2)
(2) The Feedback percent value is also scaled based on the value of adapter
Parameter 29 - [N2 Ref Scale].
Percent Speed Speed Percent
100% 70 Hz 60 Hz (3)
(3) The drive runs at 60 Hz instead of 70 Hz because Parameter 82 - [Maximum
Speed] sets 60 Hz as the maximum speed.
85.7%
50% 35 Hz 35 Hz 50%
25% 17.5 Hz 17.5 Hz 25%
0% 0 Hz 0 Hz 0%
Table 5.H PowerFlex 70EC and PowerFlex 700VC Default Example
Drive Parameters 20-COMM-H Parameter
Number Value Number Value
(1)
(1) This value is calculated as follows: 60
÷
130 x 32767 = 15123.
55 - [Maximum Freq] 130
29 - [N2 Ref Scale] 15123 82 - [Maximum Speed] 60
298 - [DPI Ref Sel] 0 (Max Freq)
Table 5.I Maximum Freq = 70 Hz Example
Drive Parameters 20-COMM-H Parameter
Number Value Number Value (1)
(1) This value is calculated as follows: 60 ÷ 70 x 32767 = 28086.
55 - [Maximum Freq] 70
29 - [N2 Ref Scale] 28086 82 - [Maximum Speed] 60
298 - [DPI Ref Sel] 0 (Max Freq)
Table 5.J Maximum Speed = 80 Hz Example
Drive Parameters 20-COMM-H Parameter
Number Value Number Value (1)
(1) This value is calculated as follows: 80 ÷ 130 x 32767 = 20164.
55 - [Maximum Freq] 130
29 - [N2 Ref Scale] 20164 82 - [Maximum Speed] 80
298 - [DPI Ref Sel] 0 (Max Freq)
Table 5.K DPI Reference Scaling = Max Speed Example
Drive Parameters 20-COMM-H Parameter
Number Value Number Value (1)
(1) When drive parameter 298 - [DPI Ref Sel] = 1 (Max Speed), the Reference and Feedback scaling
is always defined as 32767, which will cause the drive to run at the value of drive parameter 82 -
[Maximum Speed]. In this example, the drive will run at 60 Hz.
55 - [Maximum Freq] 130
29 - [N2 Ref Scale] 32767 82 - [Maximum Speed] 60
298 - [DPI Ref Sel] 1 (Max Speed)