Ethernet responses missing data
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#67 Ethernet responses missing data
I'm using an Ethernet to RS485 gateway (Gridconnect ATC-2000) so we can communicate with an RS485 MODBUS device over Ethernet. I used Realterm to connect to the gateway on the Ethernet side (so Realterm is doing a TCP connection) and in some cases, Realterm is not displaying the full MODBUS response. The weird part is one MODBUS function code works fine, while another does not. More specifically, if I send this command to the MODBUS device:
1 3 0 0 0 10 (crc)
I see the full response in Realterm no problem. But if I send this command:
1 4 0 0 0 10 (crc)
the first dozen bytes or so of the response are there, then every other byte is missing. Wireshark running on the same computer proves the data is arriving via Ethernet, but Realterm isn't displaying it all.
this is probably the usual raw vs telnet tcp mode issue. Try the other one