3 - 10 3 - 10
MELSEC-Q
3 SPECIFICATIONS
3.2 D/A Conversion Module Function
Table 3.2 shows the function of the D/A conversion modules.
Table 3.2 Function list
Item
Function
Reference section
D/A conversion
enable/disable function
(1) Specifies whether to enable or disable the D/A conversion for each channel.
(2) By disabling the D/A conversion for the channels that are not used, the
conversion speed can be shortened.
Section 3.4.2
D/A output
enable/disable function
(1) Specifies whether to output the D/A converted value or the offset value for
each channel.
(2) The conversion speed stays constant regardless of whether D/A output is
enabled or disabled.
Section 3.3.1
Synchronous output
function
(1) An analog output synchronized with the PLC CPU can be obtained.
Section 3.2.1
Analog output
HOLD/CLEAR function
(1) The output analog value can be retained when the PLC CPU module is
placed in the STOP status or when an error occurs.
Section 3.2.2
Analog output test
during PLC CPU STOP
(1) When the CH. output enable/disable flag is forced ON during PLC CPU
STOP, the D/A converted analog value is output.
Section 3.2.3
Resolution mode
(1) The resolution mode can be changed according to the application, and a
resolution setting can be selected from 1/4000, 1/12000 and 1/16000.
(2) The resolution mode setting is applicable to all channels.
(3) See Section 3.1.1 for the digital input values and maximum resolution in
normal resolution mode and high resolution mode.
Section 3.1.1
Section 4.5
3.2.1 Synchronous output function
An analog output that is synchronized with the PLC CPU can be obtained.
The analog output will be updated after the synchronous output request (YD) is set to ON
and the time specified as "PLC CPU processing time + 120 s" has elapsed.
However, the analog output will be fixed to CH1, and other channels (CH2 to CH8)
cannot be used.
Digital write from the
PLC CPU
Synchronous output
request (YD)
Analog output value
Always constant
<Program example>
Write command
DELTA YD
T0
K1
D0
K1
H0
Digital value write
Outputs synchronous
output request as a pulse