Tempo, in OctaMED works like this.
Assuming you are in BPM mode (which you should be), the main tempo slider sets the number of beats per minute. So in your case, you'd set that to 200.
The next parameter, LPB controls how many
editor lines there are to one beat. The default, from the old mod tradition, would normally be 4, meaning you get a new beat every 4 lines. If you wanted to have 1/8th of a beat resolution, you would set this to 8, for instance and space all your beats apart by 8 lines as they scroll up twice as fast as before. If you did set LPB to 8, then your default 64-line block now only represents 4 bars rather than 8.
If you were doing triplet timed music, you would set LPB to some appropriate multiple of 3 (depending on the level of precision you wanted), instead.
The last parameter, TPL is "ticks per line". This value controls the rate of the various player effects but also affects the tempo (the ticks it is referring to are, I guess, the most fundamental timing unit in octamed). The above stated value in BPM is only correct when TPL is at it's default value of 6. The player command 0090x can change this value, which you can put to good effect. For example, if you change it on each quarter beat such that you alternate it between 7 and 5 (or 8 and 4 for a more extreme effect), you get that syncopated "groove" effect that is handy for certain genres. Since the average of 7 and 5 is 6, overall the tempo remains correct.
Hope all this makes sense.
-edit-
Important note: None of the above works in legacy 5-8 channel mode, which has it's own very esoteric tempo controls. I cannot stress it enough, do not use the old 5-8 channel mode!
Here is what I'm talking about.
See in Open Mod Plug Tracker (for Windows), you merely set your BPM, and that's that.
On the Amiga side you got BPM, but you also have TPL and LPB amongst other things.
I understand how to get it into BPM mode, but then I often times need to change TPL, and when I do that, it sometimes makes BPM about useless in that moving the BPM level has no effect accept within the 1-12 range, etc.
All I want to do is set the BPM to 200BPM to match the timing of the other programs I'm using.