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Protocol Conversion Section 6-5
Note (1) The FINS header contains the following information.
• Remote destination network address (DNA): Same as for CompoWay/F.
• Remote destination node address (DA1): Same as for CompoWay/F.
• Remote unit address (DA2): Same as for CompoWay/F.
(2) The contents of the Modbus-ASCII command enclosed in the FINS mes-
sage that is sent is as follows:
Slave address (ASCII) + FUNCTION code (ASCII) + Communications
data (ASCII)
The header “:” (3A hex) and LRC+CR/LF are not required when sending
FINS. They are added automatically for serial communications.
6-5-6 Converting from FINS to Host Link FINS
A PLC slave that is connected serially to the PLC master via Host Link can be
accessed from the PLC master or personal computer (see note) using FINS
messages. Accessing a device on another network via Host Link (serial com-
munications) is also possible by using FINS messages. By converting the
FINS to Host Link FINS, the PLC can function as a Host Link master.
Note Applications such as CX-Programmer or CX-Protocol that use CX-
Server as a communications driver.
• Sent FINS message: FINS header + User-specified FINS command (see
note 1)
• Message after conversion: FINS command enclosed in Host Link header
and terminator (see note 2)
System Configuration Patterns
Access from CX-Programmer (Sending Internal FINS Messages)
The Board/Unit converts the FINS messages to Host Link FINS for sending in
this operation.
Access from Serially Connected CX-Programmer
FINS command
(To other network)
Host Link header
Terminator
Host Link FINS command
FINS command encapsulated using Host Link
(RS-232C or RS-422A/485)
FINS message
CX-Program-
mer or other
application
using CX-
Server or
CPU Unit
(CMND(490))
User-specified
FINS command
(Via serial, network,
or CPU bus)
Serial Com-
munications
Unit/Board
User-specified FINS
command
OMRON PLC (CS/CJ
Series, CVM1/CV
Series)
Serial-to-Serial Details Routing tables to
treat serial
communications
path as network
Personal computers (e.g., CX-
Programmer) connected seri-
ally (via tool bus or Host Link)
to the PLC master can access
a PLC slave that is connected
serially to the PLC master via
Host Link.
Optional
Peripheral or RS-232C port
Host Link header
Serial Communications Unit/Board
CX-Programmer, etc.
Terminator
Host Link header Terminator
Used as Host Link Master
RS-422A/485 (Host Link)
CPU Unit
CS/CJ-series or CVM1/CV-series PLC (Host Link Slave)
Protocol
conversion
User-specified
FINS command
User-specified
FINS command
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