$SimpleCache = new \Rundiz\SimpleCache\Drivers\FileSystem();
$cacheKey = 'myipsubmitted';
if (!$SimpleCache->has($cacheKey)) {
// allow form submit
// do form submit
$ttl = 5 * 60 * 60;
$SimpleCache->set($cacheKey, $ipAddress, $ttl);
} else {
// do not allow form submit
}