R2Sonic 2026, Operation Manual

Page: 233 / 254

Page 233 of 254
Version 6.3 Rev r012
Date 05-11-2022
15.14.4 Data Playback
To playback data, use bittwist.exe. You can playback data on the same computer that the data
collection program resides on by simply connecting the sonar Ethernet port to an Ethernet switch.
The Ethernet switch is only to placate the NIC. You can also send data from a remote computer to
the data acquisition computer.
The Ethernet interface number needs to be determined. Choose the interface that is connected to
the sonar system. To display Ethernet interfaces:
bittwist –d
To playback data:
bittwist -i 2 -l 0 out.pcap
This sends out.pcap to Ethernet interface 2 (-i 2) and loops continuously (-l 0). Use Ctrl-C to exit the
program.
If you don’t want to loop, use:
bittwist -i 2 out.pcap
Note:
Newer Ethernet playback utilities are better than bittwist . Ask support about a modified version of
Playcap.exe (Open Source program modified for looping) and Wireplay.exe (R2Sonic program that
can play back pcap files at full speed and you don't need to edit pcap files with bitttwiste ).
Wireplay.exe is the recommended playback utility. Wireplay is available from R2Sonic.