Rockwell Automation RECOMM-485 RS485 DFI Communications Module - Manual (Page 54)

B-8 RS485 DF1 Communications Module
Enables/disables duplicate message detection by the module.
Normally, this is set to “Enable” (default). Set to “Disable” if using a
ProSoft 3150-DFM module or any device that does not increment
the TNS (transaction number) ID.
26 Dup Msg Detect
Range: 0 = Disable
1 = Enable
Default: 1 = Enable
Type: Read/Write
Reset Required: No