Mitsubishi Electric MELSEC-A/QnA Series - Function Comparison

2 ANALOG INPUT MODULE REPLACEMENT
2 - 23
2.4.2 Function comparison
*1 For the A68AD, the resolution for voltage is 1/2000 and that for current is 1/1000 (fixed).
For the Q68AD-G, the resolution for voltage and current is 1/4000 in the normal resolution mode, while the resolution for the
voltage from -10 to 10V is 1/16000 and the resolution for the voltage in other ranges and current is 1/12000 in the high
resolution mode.
: With functions, -: Without functions
Item Description A68AD Q68AD-G Precautions for replacement
A/D conversion enable/disable
Specifies whether to enable or disable the
A/D conversion for each channel.
By disabling the conversion for the
channels that are not used, the sampling
time can be shortened.
Sampling processing
The A/D conversion for analog input values
is performed successively for each channel,
and the digital output value is output upon
each conversion.
Averaging processing
For each channel, A/D conversion values
are averaged for the set number of times or
set amount of time, and the average value
is output as a digital value.
The setting range of average
time and count differ.
Refer to Q68AD-G [User's
Manual] and then, confirm the
specifications.
Moving average takes the average of the
specified number of digital output values
measured per sampling time.
-
Primary delay filter
A digital output value is smoothed
according to the preset time constant.
-
Maximum and minimum values
hold function
The maximum and minimum values of the
digital output values are retained in the
module.
-
Resolution mode
The resolution can be switched according to
the application. The resolution mode is
batch-set for all the channels.
*1
-
Input signal error detection
function
The voltage/current outside the setting
range is detected.
-
Warning output function
(1) Process alarm
A warning is output if a digital output
value falls outside the setting range.
(2) Rate alarm
A warning is output if the varying rate of
a digital output value falls outside the
preset varying rate range.
-
Scaling function
Conversion of A/D conversion values to
preset percentage values and loading into
the buffer memory is available.
Programming steps for the scaling can be
eliminated.
-
Online module change
A module change is made without the
system being stopped.
-
Replaceable modules during
online are a process CPU and a
redundant CPU.