Host Engineering Forum

General Category => General Discussion => Topic started by: scottsutton on December 01, 2022, 10:48:42 AM

Title: TCP layer Timeout
Post by: scottsutton on December 01, 2022, 10:48:42 AM

I have a BRX that is using ModbusTCP to connect to various devices within a machine (Machine A). This layout has worked well in this machine for over a year with no issues like all my other implementations of ModbusTCP with a BRX PLC. However, the customer recently added a separate machine (Machine B) in the assembly line and they wanted to control it through ModbusTCP from Machine A. Machine B can power up and down independently of Machine A and that is the issue. The TCP layer times out if they do not power up the machines at the same time or power Machine B before powering Machine A. Once the timeout happens I cannot get the BRX to reestablish the connection. Is there a work-around for this unique situation or do they have to power down Machine A to get the connection back?

Thanks!

Title: Re: TCP layer Timeout
Post by: BobO on December 01, 2022, 11:01:33 AM

Quote from: scottsutton on December 01, 2022, 10:48:42 AM

I have a BRX that is using ModbusTCP to connect to various devices within a machine (Machine A). This layout has worked well in this machine for over a year with no issues like all my other implementations of ModbusTCP with a BRX PLC. However, the customer recently added a separate machine (Machine B) in the assembly line and they wanted to control it through ModbusTCP from Machine A. Machine B can power up and down independently of Machine A and that is the issue. The TCP layer times out if they do not power up the machines at the same time or power Machine B before powering Machine A. Once the timeout happens I cannot get the BRX to reestablish the connection. Is there a work-around for this unique situation or do they have to power down Machine A to get the connection back?

Thanks!

What firmware version is the BRX running?

And so I can better understand what you are doing, are you using MRX/MWX instructions to talk to the devices, or the Modbus scanner?

Title: Re: TCP layer Timeout
Post by: scottsutton on December 01, 2022, 11:41:45 AM

The PLC OS is version 2.8.6, so I could update that. Yes, I am using the MRX/MWX.

Title: Re: TCP layer Timeout
Post by: BobO on December 01, 2022, 01:52:20 PM

Quote from: scottsutton on December 01, 2022, 11:41:45 AM

The PLC OS is version 2.8.6, so I could update that. Yes, I am using the MRX/MWX.

There was a bug in the firmware that could hang TCP client devices indefinitely. Updating to the latest should fix the issue.

Title: Re: TCP layer Timeout
Post by: scottsutton on December 01, 2022, 02:12:08 PM

Updating did correct the issue!

Thanks!