Dm Link Communication; Overview - IDEC MICRO/I HG4G-CJT22 F-B Series User Manual

3 DM Link Communication

3 DM Link Communication

3.1 Overview

DM Link Communication reads and writes value to external devices using the MICRO/I's dedicated DM Link memory.
The device type of dedicated DM Link memory is DM.
This method uses a dedicated IDEC protocol, so a communication program is required in the external device.
DM0:
1234 5678
DM1:
For details regarding the DM Link Communication, refer to Chapter 4 "DM Link Communication" in the
WindO/I-NV4 External Device Setup Manual.
Communication Methods
●
Over the serial interface, when one external device is communicating with one MICRO/I using this communication
method it is called DM Link 1:1 communication, and when one external device is communicating with multiple MICRO/I
units, it is called DM Link 1:N communication. When external devices and the MICRO/I are communicating using DM
Link communication over the Ethernet interface (UDP protocol), it is called DM Link Ethernet (UDP) communication
DM Link 1:1 Communication
■
The external device is connected to a single MICRO/I by using a serial interface.
The Event Transmission function from the MICRO/I can be used with DM Link 1:1 Communication.
The Event Transmission function is a function that works as follows. When value in the dedicated DM Link memory of
the MICRO/I is changed, the data is transmitted from the MICRO/I to the external device.
DM0:
DM1:
DM2:
*1 HG5G/4G/3G/2G-V, HG4G/3G, HG2G-5F only
3-4
DM Link Communication
External device
999
External device
DM Link 1:1 Communication
External device
DM Link 1:1 Communication
100
150
200
WindO/I-NV4 User's Manual
HG5G-V HG4G-V HG4G HG3G-V
MICRO/I
Read
Write
Dedicated DM Link memory
HG5G-V HG4G-V HG4G HG3G-V
Read
Write
Event transmission
HG3G HG2G-V HG2G-5F HG2G-5T
Numerical Display
Destination Device Address: DM0
999
5678
Numerical Display
Reference Device Address: DM1
DM0
DM1
DM2
DM8190
DM8191
HG3G HG2G-V HG2G-5F HG2G-5T
MICRO/I
Dedicated DM
Link memory
MICRO/I
DM0:
Dedicated DM
DM1:
Link memory
DM2:
HG1G HG1P
*1
.
HG1G HG1P
0 100
0 150
0 200