71
Rev Version 1.4.1
Rev Version 1.4.1
Typical results for this setup are shown below.
Data Throughput
– Modbus (Polls per Minute)
4800 Baud (2 level FSK)
9600 Baud (4 Level FSK)
20 Words @ maximum Scan rate
– No Compression
72 Ppm
91 Ppm
20 Words @ maximum Scan rate
– With Compression
89 Ppm
113 Ppm
120 Words @ maximum Scan rate
– No Compression
50 Ppm
58 Ppm
120 Words @ maximum Scan rate
– With Compression
89 Ppm
113 Ppm
FTP Fill Transfer Test
Another means for gaging the data throughput performance of the modem is to transfer a known data file using
FTP (File Transfer Protocol) and time how long it takes for the file to download. To perform this test you will need a
computer at each end of the radio link. One of the PCs will need to run an FTP server application, such as Fillzilla
or Cerberus Server, and the other PC needs to run as an FTP client. Because the WI-MOD-xxx-E-5W has a reduced
throughput compared to other Ethernet modems, you will need to adjust the connection timeout under the settings
within the application. Below are some estimated throughputs for FTP transfer using different radio baud rates.
NOTE The results will vary depending on the type of file being sent and whether compression is enabled.
Data Throughput
– FTP (file transfer)
4800 baud (2 level FSK)
9600 baud (4 Level FSK)
100 KB text file
– No Compression
294 sec @ 0.34 Kbps
185 sec @ 0.72 Kbps
100 KB text file
– With Compression
65 sec @ 1.54 Kbps
46 sec @ 2.17 Kbps
134 KB jpg file
– No Compression
404 sec @ 0.33 Kbps
185 sec @ 0.72 Kbps
134 KB jpg file
– With Compression
215 sec @ 0.62 Kbps
183 sec @ 0.73 Kbps
Iperf Throughput Test
A more thorough test is to perform a throughput test that will check the amount of data that can be reliably
achieved via the wireless link. Software tools that can be used to check the data throughput include FTP (File
Transfer Protocol), Iperf, and Qcheck. The preferred application is
“Iperf,” which is an MS-DOS-based bandwidth
measurement application that is run on a laptop or PC at each end of the radio link. The Iperf/Jperf application can
be downloaded from http://sourceforge.net/projects/iperf/.
Configure one Iperf session on one of the computers as a server, and another session on the other end of the
link as a client. The Iperf client will then pass data over the link, calculate the results, and display the throughput
accordingly. See Appendix G for a detailed procedure on using Iperf to externally check radio data throughput.
5.4 Statistics
The Statistics page is used for advanced debugging purposes, and is accessed by clicking Statistics on the menu.
The page provides detailed information about the state and performance of the WI-MOD-xxx-E-5W , and allows you
to gather information about how the module is connected and communicating. Dynamic list boxes display statistics
about various functions (see Figure 76). This information is useful to WEIDMULLER technical support personnel in
diagnosing problems with the module.
NOTE When updating the Statistics page, you need to hold down the <CTRL> key while clicking Refresh
to ensure that the most up-to-date information is displayed.
