With either the Icom IC-718 or the IC-7200 and the LDG IT-100 tuner, the transceiver may be set so that tuner operation is completely automatic. I mean completely. You don't even press the Tune buttons on either the tuner or the transceiver.
For automatic "Tune on PTT" operation, the PTT button is keyed and if the radio senses that SWR is high, it will automatically begin a tune cycle, which takes from 1 to 4 seconds. Tuning will occur after a band change, as the tuner C and L settings that are correct for one band will probably not be correct for another. If there is a big change within a band, such as working PSK-31 on 7.070 mhz, then going to phone on 7.285 mhz, retuning may be required. But a smaller change, such as moving from 3.910 mhz to 3.925 mhz probably will not. Nor will the radio return in the middle of a QSO or as long as you remain on or near a previously tuned frequency.
When a successful tune occurs the tuner will store that combination of L and C settings in its memory. The next time you return to that frequency, or a frequency nearby, the tuner will first go to the previously saved setting and check SWR. If close, no further tuning will occur. You will hear just a single click of the relays. If it requires returning, it will probably be quick, just a few clicks, as it is beginning with a previously good setting.
All you do is key the mic, and if the transceiver and tuner begin tuning, just wait a few seconds until finished and then begin operation.
To set up the Icom IC-7200 for fully automatic operation of the LDG IT-100 tuner refer to page 77 of the manual. There is no need to select AT-180 or AH-4 tuners for the IC-7200 as is necessary for the IC-718.
Set Mode, PTT Tune, set to On for completely automatic operation.
Set to Off if you wish it to tune only when you push Tuner button on the IC-7200, or the Tune button on the IT-100 tuner.
So why would you want fully automatic operation? My club has two IC-7200s (one is mine, one is the club's) in our club station. In addition, my personal portable "go-kit" has an IC-718 with LDG IT-100, too. These radios will be used by a number of hams with varying skills, experience, and familiarity with these radios. It was felt that we should keep operation as nearly KISS (Keep It Simple, Stupid!) as possible.
My question is, with the radio and tuner having this capability, why would you not want to do this? You can still initiate a tune at any time via the buttons on the radio or tuner.