There are three ways of sending tap tempo information with the FCB1010: one for effects expecting some kind of controller message from the 'tap' button (some Lexicon units, for example), one designed for effects that expect a Note On message from the 'tap' button and the other for effects units that actually don't HAVE a tap tempo function, but do have delay time controllable from a MIDI continuous controller.
In all cases, once you've got it set up, you need to use the FCB1010 in Bank Mode, and use the same button you use to select the patch as the tap tempo button.
Units expecting controller message
Read the manual for the effect unit, and find out which controller number and value you need to send. Set the relevant patch to send that controller number and value when selected (remember you'll need to set the MIDI channel for CNT1 or 2 in Global Setup (manual p10) and enable that controller by a long press on the corresponding footswitch in Preset Programming mode).
Units expecting Note On message
Read the manual for the effect unit, and find out which note number you need to send. Set the relevant patch to send that note number when selected. Again, remember the MIDI channel for the Note On message needs setting in Global Set up, and needs enabling for that preset.
Units without Tap Tempo feature
Read the manual for the effect unit, and find out which MIDI controller can be used to set delay time, how long the maximum delay time (lets call it Tmax) is in milliseconds, and what controller value (Vmax) this corresponds to. If the maximum delay time is less than 1270ms, you have no problem: follow the procedure on pp14-5 of the manual.
If it is greater than 1270ms, grab a calculator and work out:
new Vmax = Vmax * 1270 / Tmax
new Tmax = 1270
Use these new values in the procedure on pp14-5 of the manual. Note that you must remember to disable CNT1 in the patch if you're using this tap tempo method.
You probably won't get as fine a control over tap tempo with this 'hack' method, since the delay time will step in amounts of Tmax / V max ms. For (say) a 600ms maximum delay this will be in steps of approximately 5ms, which is probably not too bad.