Pariah Planet by Murray Leinster

There was no answer from the ground when breakout came and Calhoun drove the Med Ship to a favorable position for a call. He patiently repeated, over and over again, that Med Ship Aesclipus Twenty notified its arrival and requested coordinates for landing. There should have been a crisp description of the direction from the planet's center at which, a certain time so many hours or minutes later, the force-fields of the grid would find it convenient to lock onto and lower the Med Ship. But the communicator remained silent.

"There is a landing-grid," said Calhoun, frowning, "and if they're using it to load fresh meat for Dara, from the herds I'm told about, it should be manned. But they don't seem to intend to answer. Maybe they think that if they pretend I'm not here I'll go away."