Specifying a base channel number

By default, xfServerPlus uses 243 as the base channel number. This is the channel number that xfServerPlus tries first whenever it needs to open a channel.

For example, when opening the SMC files (cdt.ism and cmpdt.ism), xfServerPlus attempts to use channels 243 and 244. If 243 is not available, it tries 244, then 245, and so on until an open channel is found.

If your Synergy server applications use hard‑coded channels that are in the range used by xfServerPlus, you may receive a “Channel is in use” error ($ERR_CHNUSE). To avoid this problem, you can set XFPL_BASECHAN in the xfpl.ini file to specify that a different base channel number be used. Valid values are 2 through 254.

For example, if you set


xfServerPlus will attempt to open the SMC files on channels 150 and 151. If 150 is currently in use, xfServerPlus will try 151, then 152, and so on until it finds an open channel. Should xfServerPlus reach channel 255 without finding an open channel, it will go to XFPL_BASECHAN  –  1 (149 in our example) and continue down from there to channel 1.

If you use hard‑coded channels in your code, you should select a base channel number that is not likely to cause interference with your applications. You may also want to consider modifying your code to use available channels rather than hard‑coded channels.