This article explains why you could be getting a timeout error when you try to communicate with an Anybus Communicator Modbus TCP server.
APPLICABLE PRODUCTS
- ABC3028
- ABC3128
- ABC4011
- ABC4016
- ABC4017
- ABC4018
PRE-REQUISITES
- A Modbus TCP Client
- Anybus Communicator with a Modbus TCP server interface
- HMS IPConfig
PROBLEM DESCRIPTION
Whenever you try to establish a communication between your Modbus TCP Client PLC engineering tool or your Modbus TCP Client simulation tool, you get a timeout error.
RESOLUTION
If you have an Anybus Communicator with a Modbus TCP server interface, and you get a timeout error each time you try to communicate with it using your Modbus TCP client, then you should check the IP configuration of the Anybus Communicator.
As you know, on the Anybus Communicator, apart from the two fieldbus/Industrial Ethernet ports, you also have a Config port, reserved for accessing the web interface for the configuration.
In case of an Anybus Communicator with a Modbus TCP server interface, it is important that the Modbus TCP server interface and the Config interface have different IP settings. As you will see in the example below, if you assign the same IP address to those two interfaces, you will get a timeout error each time you try to establish communication with the Modbus TCP Client.
In this example, we use the ABC4017 PROFINET IO Device / Modbus TCP server.
The PROFINET Master Simulator will be used as PROFINET Master, and Modbus Poll will be used as Modbus TCP Client.
We have the same IP address assigned to the Config and Modbus TCP server interfaces
The result is a timeout error each time we try to establish a Modbus TCP communication
Let's now assign a different IP address to the Modbus TCP server interface
We can see that the communication is now successful