Omron SYSMAC CJ1W-SCU21-V1, Operation Manual

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11
Protocol Overview Section 1-3
1-3-4 Loopback Test
A connector with a loopback connection is attached to the specified serial port
to perform loopback tests. Data is sent to this port, and the communications
circuit is tested by comparing the transmitted data and the data returned by
loopback.
Note This loopback test is performed inside the specified serial port. It is not a loop-
back test using the RS-232C or RS-422A/485 communications path.
1-3-5 Serial Gateway Mode
The received FINS message is automatically converted to either Compo-
Way/F, Modbus-RTU, Modbus-ASCII, or Host Link FINS, depending on the
type of message.
CompoWay/F, Modbus-RTU, and Modbus-ASCII
FINS Host Link
1-3-6 No-protocol Mode
No-protocol mode supports data receiving or data sending using data receive
or send commands, respectively (see note). No-protocol mode, however, can
be used only with CS/CJ-series CPU Units with unit Ver. 3.0 or later in which a
Serial Communications Board or Unit with Unit Ver. 1.2 or later is installed.
Use the no-protocol mode when the data send and receive protocols are to be
created by the user, or when connecting to devices that only receive or send
data, such as bar code readers, or printers.
The loopback test results
are stored.
Loopback test switch
Loopback test
CMND
FINS
FINS
CompoWay/F (See note.)
CompoWay/F (See note.)
CompoWay (See note.)
Send FINS command
Network
Serial
Communications
Unit
Serial
Gateway
CompoWay-compatible
OMRON component,
Modbus-RTU-, or Modbus
ASCII-compatible device
Note: Or Modbus-RTU
commands or Modbus
ASCII commands
CMND
FINS
FINS
FINS
FINS
Network
Host Link
header
Host Link
header
Host link terminator
PLC (Host Link)
Serial
Gate-
way
Host link
terminator
Send FINS
command
CX-Programmer or other
Programming Device for
using CX-Server as a
communications driver