3 DM Link Communication
3-4 WindO/I-NV4 User’s Manual
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.
●
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
*1
.
■ 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.
*1 HG2J-7U, HG5G/4G/3G/2G-V, HG4G/3G, HG2G-5F only
3 DM Link Communication
HG3G
HG2G-5FHG5G-V HG4G-V HG3G-V HG2G-V HG2G-5T
HG4G HG1G HG1P
HG2J-7U
MICRO/I
999
5678
External device
DM Link Communication
Read
Write
DM0:
999
DM1:
1234 5678
DM0
DM1
DM2
DM8190
DM8191
Dedicated DM Link memory
Numerical Display
Destination Device Address: DM0
Numerical Display
Reference Device Address: DM1
For details regarding the DM Link Communication, refer to Chapter 4 "DM Link Communication" in the
WindO/I-NV4 External Device Setup Manual.
HG3G
HG2G-5FHG5G-V HG4G-V HG3G-V HG2G-V HG2G-5T
HG4G HG1G HG1P
HG2J-7U
MICRO/I
Dedicated DM
Link memory
External device
DM Link 1:1 Communication
Read
Write
MICRO/I
Event transmission
Dedicated DM
Link memory
External device
DM0: 0
DM1:
0
DM2:
0
100
150
200
DM0:
100
DM1:
150
DM2:
200
DM Link 1:1 Communication