Fieldbus Reference Scaling - ABB ACS310 User Manual

Fieldbus references
Reference selection and correction
Fieldbus reference (called COMM in signal selection contexts) is selected by setting a
reference selection parameter –
COMM*AI1. When
fieldbus reference is forwarded as such without correction. When parameter
is set to COMM+AI1 or COMM*AI1, the fieldbus reference is corrected using
1106
analog input AI1 as shown in the following examples.
Setting
COMM COMM(%) · (MAX-MIN) + MIN
+AI1 + (AI(%) -50%) · (MAX-MIN)
Corrected
reference (Hz)
50
AI = 100%
25
0
0%
Corrected
reference (Hz)
50
40
AI = 100%
25
AI = 50%
10
0
0%
Maximum limit is defined by parameter
Minimum limit is defined by parameter
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1103
REF1 SELECT or
1103
When COMM > 0
AI = 50%
AI = 0%
50% 100%
COMM
REF (%)
Max limit
AI = 0%
Min limit
COMM
REF (%)
50% 100%
Fieldbus control with embedded fieldbus 271
or – to COMM, COMM+AI1 or
1106
REF2 SELECT is set to COMM, the
1106
COMM(%) · (MAX-MIN) - MIN
+ (AI(%) -50%) · (MAX-MIN)
COMM
Max limit
REF (%)
Min limit
Min limit Max limit
COMM
REF (%)
Min limit
Max limit
REF1 MAX /
1105
REF1 MIN /
1104
When COMM < 0
-100% -50%
AI = 100%
AI = 50%
AI = 0%
Corrected
reference (Hz)
-100% -50%
AI = 100%
AI = 50%
AI = 0%
Corrected
reference (Hz)
REF2 MAX.
1108
REF2 MIN.
1107
or
1103
0%
0
-25
-50
0%
0
-10
-25
-40
-50