Loopback Test; Loopback Test (Command: 16H) - Mitsubishi Electric FX3U-ENET-ADP User Manual

FX -ENET-ADP User's Manual
3U
7.7

Loopback Test

A loopback test checks whether or not the communication function between an external device and the
Ethernet adapter operates normally. The examples show the control procedure using this function.
Caution
• A loopback test checks whether or not the connection between the external device and the Ethernet
adapter is correct and that the data communication function operates properly when the Ethernet adapter
is started up or when a problem occurs.
• Use the following data for loopback tests. Send the head part first.
- When communicating in binary code
Maximum of 254 bytes of numerical values (00 to FFH).
- When communicating in ASCII code
Maximum of 254 single-byte characters ("0" to "9", "A" to "F").
7.7.1

Loopback test (command: 16H)

The examples shown in this section explain the control procedure for an external device performing a
loopback test with the Ethernet unit.
The order and content of data items of the areas marked by " * " shown in the control procedure diagram differ
depending on the module used as well as the frame and format used for communication.
For details, refer to Subsection 7.3.2.
[Control procedure]
1) Performing a loopback test while communicating in binary code
(Data name)
External device
side
(Example)
(Data name)
PLC side
(Example)
86
Designated byte length+5bytes
*
L H
16 FF 0A 00
H H H H
7 Communication Using MC Protocol
*
96 00
H H
Designated byte length+3bytes
7.7 Loopback Test