User`s manual

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MELSEC-Q
3 SPECIFICATIONS
3.2.5 Rate control function
(1) The increment and decrement of the analog output value per conversion cycle are
restricted to prevent a sudden change of the analog output value.
(2) For the rate control function, the rate control enable/disable setting (buffer memory
address 46: Un\G46) allows enable/disable of the rate control to be specified for
each channel.
To enable the rate control, write "0" to the bit position corresponding to the
channel number and turn ON the operating condition setting request (Y9). The
default is all-channel disable.
(3) Set the increase digital limit value and decrease digital limit value (buffer memory
addresses 70 to 73: Un\G70 to Un\G73).
Example) The control example in the following case is indicated below.
Output range: -10 to 10V
Increase digital limit value: 100
Decrease digital limit value: 100
Digital input value
500
400
300
200
100
0
312.5
250.0
187.5
125.0
62.5
0.0
0 102030405060708090100110120
Time (ms)
Digital input value
Analog output value
Voltage of analog
output value (mV)
(4) If the operation of the PLC CPU varies at the setting of D/A conversion enable,
D/A output enable and analog output clear, the rate control functions as indicated
below.
• If the PLC CPU has switched from RUN to STOP (error): Rate control does not
function.
• If the PLC CPU has switched from STOP (error) to RUN: Rate control functions.
RUN
STOP (error)
Offset value
Analog value converted
from digital input value
Analog output value
PLC CPU status
RUN
Analog value converted
from digital input value
Rate control valid