Function Comparison - Mitsubishi Electric MELSEC-A/QnA Series Handbook

2
ANALOG INPUT MODULE REPLACEMENT

2.7.2 Function comparison

Item
A/D conversion enable/disable
Sampling processing
Averaging processing
Maximum and minimum values
hold function
Temperature drift
compensation function
Resolution mode
Online module change
*1 For the A68ADN, the resolution for voltage and current can be set to 1/4000, 1/8000, or 1/12000.
For the Q68ADV/I, 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.
2
- 47
Description
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.
The A/D conversion for analog input values
is performed successively for each channel,
and the digital output value is output upon
each conversion.
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 maximum and minimum values of the
digital output values are retained in the
module.
Errors arising from changes in the ambient
temperature of the module are
automatically compensated for to improve
conversion accuracy.
The temperature drift compensation
function can be performed at (A/D
conversion time for all channels) + 160µs.
The resolution can be switched according to
the application. The resolution mode is
*1
batch-set for all the channels.
A module change is made without the
system being stopped.
: With functions, -: Without functions
A68ADN Q68ADV/I Precautions for replacement
The sampling processing time
changes depending on the
number of channels used
(number of channels set to A/D
conversion enable) and whether,
with or without the temperature
drift compensation function.
(a) Without temperature drift
compensation function
(processing time) =
(number of channels used) ×
80 (µs /1 channel)
(b) With temperature drift
compensation function
(processing time)=
(number of channels used) ×
80 (µs /1 channel) + 160µs
The setting range of average
time and count differ.
Refer to [Analog-Digital
Converter Module User's
Manual] and then, confirm the
specifications.
-
-
Replaceable modules during
- online are a process CPU and a
redundant CPU.