GE C30 Instruction Manual page 281

CHAPTER 5: SETTINGS
Hardware and software is provided to generate DCmA signals that allow interfacing with external equipment. Hardware
details are contained in chapter 3. The DCmA output channels are arranged in a manner similar to transducer input or CT
and VT channels. The user configures individual channels with the settings as follows.
The channels are arranged in sub-modules of two channels, numbered 1 through 8 from top to bottom. On power-up, the
relay automatically generates configuration settings for every channel, based on the order code, in the same manner used
for CTs and VTs. Each channel is assigned a slot letter followed by the row number, 1 through 8 inclusive, which is used as
the channel number.
Both the output range and a signal driving a given output are user-programmable via the following settings menu (an
example for channel M5 is shown).
The relay checks the driving signal (x in equations below) for the minimum and maximum limits, and subsequently re-
scales so the limits defined as
following equation is applied:
where
x is a driving signal specified by the
I and I are defined by the
min max
k is a scaling constant calculated as:
The feature is intentionally inhibited if the
– < 0.1 pu. The resulting characteristic is illustrated in the following figure.
MIN VAL
Settings
— This setting specifies an internal analog value to drive the analog output. Actual values
DCMA OUTPUT F1 SOURCE
(FlexAnalog parameters) such as power, current amplitude, voltage amplitude, power factor, etc. can be configured as
sources driving DCmA outputs. See Appendix A for a list of FlexAnalog parameters.
— This setting allows selection of the output range. Each DCmA channel can be set independently
DCMA OUTPUT F1 RANGE
to work with different ranges. The three most commonly used output ranges are available.
— This setting allows setting the minimum limit for the signal that drives the output. This setting is
DCMA OUTPUT F1 MIN VAL
used to control the mapping between an internal analog value and the output current. The setting is entered in per-unit
values. The base units are defined in the same manner as the FlexElement base units.
C30 CONTROLLER SYSTEM – INSTRUCTION MANUAL
and match the output range of the hardware defined as
MIN VAL MAX VAL
I if x <
MIN VAL

min

I if x >
I = MAX VAL

max
out

  I
k x
MIN VAL

–
setting
SOURCE
setting
RANGE
I
–
max
k = ------------------------------------------- -
MAX VAL
–
and
MAX VAL MIN VAL
Figure 5-78: DCmA output characteristic
I
max
I
min
DRIVING SIGNAL
MIN VAL
+ otherwise
min
I
min
MIN VAL
settings are entered incorrectly, for example when
MAX VAL
842739A1.CDR
TRANSDUCER INPUTS/OUTPUTS
. The
RANGE
Eq. 5-4
Eq. 5-5
MAX VAL
5-163
5