Universal Robots Forum

Connect UR Robot with Keyence KV8000 PLC using modbus TCP/IP

Hi. I am using a Keyence KV 8000 PLC communicating with UR5e Robot through Modbus TCP/IP. The PLC is Modbus client and the robot is Modbus Server. I have successfully open socket KV8000 and connected to the robot. When I try to send read holding register command to the robot. PLC receive error which indicates that Communication Destination Closed. May I know how to solve this error?

Hi @wongyy,

I do not have the experience in using modbus tcp with Keyence PLC. Perhaps, you could share more info. or materials about how to use the PLC in modbus TCP. As I know, there is also specific Keyence communication module to provide the modbus TCP function. Are you using this specific module or just using the embedded Ethernet port with special function block to achieve the modbus TCP? If any, welcome to share these documents.

About the modbus server in UR, the server is activated all the time and one thing worthwhile to mention is that you may need to add 4000 to the address offset in order to read/write the correct address.

Please read this article to see whether this is helpful.


I have successfully communicate the robot. Thank you very much on your advice and support

@wongyy , OK but what is the key to solve your problem?


I have successfully comm the UR Robot.

Thank you for your advice and support.


Wong Yau Yun

Software & Control Enigneer


No.9, Kaki Bukit Road 1 #02-06/07/08

Eunos Technolink, Singapore 415938

Tel : (65) 67488007

Hp : (65) 84147860

Fax : (65) 67489232

Web : www.yac.com.sg; www.yac.co.jp