Introduction; Features - Mitsubishi Electric MELSEC A Series Manual

1. INTRODUCTION

1. INTRODUCTION

1.1 Features

This manual gives specifications, handling, programming procedures, etc. for the
A68ADN analog to digital converter module (hereafter called the A68ADN) for use
with MELSEC-A series PC CPU modules.
An A68ADN converts analog signals (voltage or current) into 16-bit, signed binary
digital values, as shown in the following figure.
Initial setting
PC CPU
(averaging
processing
TO instruction
designation,
FROM
etc.)
instruction
Digital value
read
Digital value
read
FROM
Instruction
Figure 1.1 Analog to Digital Conversion
A chart showing differences between the A68ADN and the A68AD, A68AD-S2, and
A616AD is given in Appendix 1.
(1) 8-channel analog to digital (hereafter A-D) conversion is possible with a single
module.
The A616ADN has 8-channel A-D conversion capability, with each channel
selectable for voltage or current input.
(2) 1/12000 high resolution (all channels)
Resolution is selectable from 1/4000, 1/8000, and 1/12000.
digital values can be obtained. Resolution setting applies to all channels.
(3) Averaging processing by designating time or frequency (for each channel)
In addition to sampling processing (in which the digital value obtained in A-D
conversion is output each time the A-D conversion is executed) averaging
processing can be done in a designated time or frequency. The A-D conversion
mode is selectable for each channel.
A68ADN
Buffer memory
Setting data
Digital value
Digital value
Analog to digital conversion
1 − 1
MELSEC-A
(Input terminal)
0 to ±10 V or
0 to ±20 mA
Channel 1
0 to ±10 V or
0 to ±20 mA
Channel 8
High resolution
Analog
output
device
Analog
output
device