Operation Techniques
73
- up to 16 multiplexed channels. For each channel, the measured quantity is
specified by the user. For the available parameters, see
Table 1-1
.
Switching the multiplexed channels takes approximately 200 ms. This does not
include the measuring time, which will vary for different parameters.
If no status inputs are allocated for the analog multiplexer, the analog output will be
non-multiplexed. In this case, the output parameter will be the one configured for the
output channel #1.
Analog Output Scales
Each channel can be independently scaled for the certain parameter by specifying its
low (zero) and high (full) scales. The first will correspond to zero offset (0/4 mA),
and the second - to the full scale (20 mA) current output. For the parameter scales,
any value within the parameter range can be specified. The only exception is the
signed power factor, for which the output scales are set permanently to the range of
-1.00 to 1.00, and the center of the scale corresponds to 1.00 as in electromechanical
power factor meters. For analog parameter scales, refer to
Table B-4b
from
Appendix B
.
For analog output current evaluation (except the signed power
factor), use the
following conversion formula:
I analog
=
−
×
−
−
(
_
_
)
(
_
)
_
_
Measured parameter
Zero scale
Zero offset
Full scale
Zero scale
20
To define measured parameter upon analog output current (except the signed power
factor), use the next conversion:
Measured parameter
Full scale
Zero scale
Zero offset
Zero scale
_
(
_
_
)
_
_
=
×
−
−
+
I analog
20
where:
I analog
- analog output current, mA
Measured_parameter - measured value in appropriate engineering units
Full_scale
- user defined parameter high scale, engineering units
Zero_scale - user defined parameter low scale, engineering units
Zero_offset = 0/4 mA (factory set)
