128
6 F 3 B 0 3 6 2
7.4 Remote Port Loopback (for an Ethernet Port)
This request sends test data to the specified remote Ethernet Port (T2N/T3H) and verifies that
transmission is being performed correctly by receiving that data looped back from the remote port.
A user program must compare the transmitted and received data for equivalence.

Remote port loopback request (using the SEND instruction)

a. Function
This request sends test data to the specified remote Ethernet Port (T2N/T3H) and verifies that
transmission is being performed correctly by receiving that data looped back from the remote port.
The T2N OS creates the test data.
b. Transfer parameters
A3100H Module designation
A+1 CMD = 000FH CMD number
A+2 WordSize Loopback data length: 1 to 485 words
A+3 SRID Send data storage register type code
A+4 SRegNO Send data storage register number
A+5 DRID Loopback data storage register type code
A+6 DRegNO Loopback data storage register number
A+7 Timecnt Timer count
A+8
A+9
D-IPAddress Loopback destination IP address
(The input procedure is the same as that for the parameter
setup request.)
A+10 D-UDP PortNO
c. Status (See figure 4.3 for details on bits C, D, E and F.)
FEDCBA9876543210
B0000 TermSTS
B+1 Detailed information (Only valid when TermSTS = 0BH.)
d. Important items
This request cannot be executed unless message transmission is enabled with an operating
mode control request.
In response to a request from a user program, the T2N OS performs the processing using the
Ethernet Port PC link protocol.
User programs on the loopback destination do not take part in this operation.
A user program must compare the transmitted and loopback data for equivalence.
A transfer word count error (TermSTS = 09H) occurs if the loopback data length exceeds the
range 1 to 485 words (or 1 to 323 words for the T and C registers).
A register specification error (TermSTS = 01H) occurs if a value other than a stipulated value
is specified for the register type codes (SRID/DRID).
A register specification error (TermSTS = 01H) occurs if 0007H (the T register) is specified
for the send data storage register type code and a register other than the T register is specified
for the loopback data storage register type code. This also holds for the C register.
A boundary error (TermSTS = 0AH) occurs if a range spanning both the base T registers (0 to
511) and the expansion T registers (512 to 999) is specified for the T register.
Loopback destination message transmission UDP port number