Mitsubishi Electric MDS-B-SPJ2 Series Specification Manual page 103

(5) Output magnification setting
The output magnification of the data to be D/A output is set in SP255 and SP256.
The output data (DATA) is calculated using equation 1.
DATA = Actual data SP255 (or SP256)
The D/A output specifications of the output data are shown in Fig. 1 below.
∗
When the data = 0, the output is 5V. (0 offset: 5V)
When the max. data = 127, the output is 10V.
When the min. data = -128, the output is 0V.
(Note) The D/A output specifications for speedometer output and load meter output data are
shown in Fig. 2 below. ∗ When the data = 0, the output is OV.
D/A output voltage
+10V
+5V
0V
− 128
(Example 1) Current command and current feedback
The data unit is a value equivalent to 100% when the actual data = 4096.
Thus, for a +120% current feedback, 4915 is output (actual data = 4096 x 1.2 = 4915).
When parameter: SP255 (SP256) is 256 (magnification =1), the D/A output voltage is
determined by equation 1,
DATA = 4915 > +128
and the D/A output voltage max. value is exceeded.
Thus, the setting value of parameter: SP255 (SP256) in this case is as follows:
DATA = 4915 ∗ {setting value} /256 < 128
From this,
{setting value} < 6.666٠٠٠ (= 128 ∗ 256/4915)
The data can be confirmed by setting SP255 (SP254) to 6.
The D/A output voltage value at this time is as follows:
D/A output voltage = 5V + {4915 × 6/256 x (5V/128)} = 9.5V
The waveform examples are shown on the following page.
6. Status Display and Parameter Setting
256
DATA
0 +127
Fig. 1
6 − 23
Equation (1)
D/A output voltage
+10V
+5V
0V
− 128
0
Fig. 2
DATA
+127