Omron K6PM-TH, User Manual

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6 Monitoring and Setting with the Modbus TCP
6 - 2 K6PM-TH Thermal Condition Monitoring Device User’s Manual (H231)
6-1 Outline
This section provides an overview of how to monitor the K6PM-TH using the Modbus TCP.
Modbus TCP is a communications protocol that uses TCP/IP to communicate with host devices such as
PLCs.
This communications protocol allows host devices with a TCP/IP socket interface to read and write the
internal data of the K6PM-TH.
Note The socket is an interface for using TCP directly from the user program.
The host device specifies the IP address of K6PM-TH and TCP port number of 502 (01F6 hex) and opens
the socket in Active. After that, it sends Modbus TCP request and reads and writes the internal data of the
K6PM-TH.
In addition, Modbus TCP can be connected to up to two clients simultaneously.
Request
Response
Main Unit (server)
Specify the IP address of the Main Unit, and the TCP port
number 502, and send a request to open the TCP/IP connection.
Receives the request.
Sends a Modbus TCP request.
Returns the response.
Requests to close the TCP/IP connection.
Receives the request.
Main Unit
server
Host device
Client
Host device (client)
with TCP/IP socket
interface