Regarding the bug (183), has this been fixed in Raspbian Stretch? This is the version we are running. The packet loss I'm referring to is the failure of the RevPi to respond in a timely manner to the initial query. Is there anything in the driver layer that could account for this?

The maximum latency between the RevPi and any of the RS485 slave devices is 600 msec. This value is the retry count * timeout which is 3*200 msec or 600 msec total. The retry count and timeout values are specified in the Modbus protocol. Normally, the round trip processing time is on the order of 20...

Attached is a png of the hardware setup. In the diagram, the RevPiConnect acts as a Modbus gateway passing on TCP/IP read/write requests to the RS485 slave devices. The slave device 64 occasionally responds to a valid Modbus RTU request with an exception response. We know this is incorrect and handl...

The issue with the RS485 device is that it responds to a valid Modbus read register request with a value exception response. We know is this an error and handle it in the code that services the read request on the RS485 side. The problem we are trying to solve is unrelated to the RS485 devices. The ...

Hi Zhan, We are running our own Modbus protocol purchased from Proconx Corporation. FieldTalk Modbus master and Slave C++ available at https://www.modbusdriver.com/shop/index.php?cPath=48. The reason we use this software is to handle a known issue with one of our RS485 devices; essentially, it invol...

Simon,

Attached is a zip file of the kernel logs of one of the Kunbus Rasp. Pi's that had the TCP/IP communication problem. I expect more to follow soon.

Regards,
John C.

Hello Simon, Thank you for your assistance. Attached is the WireShark log file. The Software we run on the PC is DeltaV overlaid with Thermo Fisher's TruBio Sofware. DeltaV and the PC are Emerson Corporation's products and TruBio is a Thermo Fisher product so I don't think this will be a practical f...

Hi Dirk, There is no os-release, just image-release. cat /etc/revpi/image-release gives 2018-07-17-revpi-stretch. The config.rsc is attached. The RevPi is used as a TCP to RS485 gateway. The RS485 side has two slave devices with Modbus ID's of 1 and 64 respectively. The value 1 is an RS485 Wago and ...

Hello, Have any TCP/IP networking problems been reported for the RevPiConnect? Specifically, has anyone reported the Pi acknowledging a query for data but never actually responding with the data without the requesting host initiating a TCP Retransmission? I am running a RevPiConnect as a Modbus gate...