4.2 Tag Communication Function
4.2.2 Class3 Tag communication
(a) Data type of the target device
The data type of the EtherNet/IP module must match that of the target device.
For the Data Type other than INT or DINT, register and set it using the "User
Define" window. (
(b) Tags that can receive read or write requests
Only the tags set as "Target" in "Class3/UCMM Tag Parameter" can accept the
Tags set as "Originator" do not accept any request from the other device.
(c) When "Application Trigger" is set for "Trigger" in "Class3/UCMM Tag Parameter":
Send a read or write request within the following timeout time.
Timeout time = RPI
When the target device failed to receive a request within the timeout time, a
timeout is detected and the connection is disrupted.
* 1 Considering possible transmission delay on the Ethernet network, make the request interval
shorter than the timeout time.
(d) Time required to recognize the Application Trigger request
(Class3/UCMM)(Un\G27072 to Un\G27087)
A maximum of 10ms is required after the Application Trigger request
(Class3/UCMM)(Un\G27072 to Un\G27087) is set to on.
(e) When the data transmission delay is lengthened
When the line is highly-loaded or unstable, the ACK of TCP from the target device
may not be receivable.
In this case, the EtherNet/IP module sends the data after 10 seconds which
lengthen the transmission delay time by 10 seconds from normal delay time.
If the above case frequently occurs, check the connectivity of cables and take
measures such as reducing the line load by increasing the setting value of RPI.
Section 7.9.5 "User Define" window)
Time Out Multiplier