Technical data

Chapter 4 – Communication
RS485 and RS232 Adapter Installation and Start-up Guide 4-9
Fieldbus Reference Scaling
Fieldbus references are scaled as follows:
Reference 1: 20000 EXT REF1 MAX (Hz, parameter 1105). Scaling
Parameter 1104 EXT REF1 MIN is not used.
Reference 2: 10000 EXT REF2 MAX (%, parameter 1108). Scaling Parameter
1107 EXT REF2 MIN is not used.
Fieldbus Reference
Fieldbus reference is selected by setting a reference selection parameter –
1103 EXT REF1 SELECT or 1106 EXT REF2 SELECT – to COMM,
COMM+AI1 or COMM*AI1. The latter two enable correction of the fieldbus
reference using analogue input AI1. The following table explains these
selections. Note that the analogue input value is a percentage value (0-100 %)
which can be seen in parameter 0118 AI1. When the analogue input is 50 %,
the correction is 0. When the input is <50 % (>50 %), the correction reduces
(respectively increases) the reference used.
Table 4-7 Correcting the fieldbus reference through analogue input.
Parameter
Setting
Effect of AI1 Value on Fieldbus Reference
COMM None
COMM+AI1 Corrected fieldbus reference = given fieldbus reference + analogue
input AI1 value
COMM*AI1 Corrected fieldbus reference = given fieldbus reference * analogue
input AI1 value / 50 %