Trade O Mats

The Trade-O-Mats allow to trade items, fluids or energy between players.
There are three Trade-O-Mats in IC2C - Trade-O-Mat, which sells items, Fluid-O-Mat, which sells fluids, and Energy-O-Mat, which sells energy. The Trade-O-Mats can pull from any Personal Storage that belongs to you.

Selling

The basic Trade-O-Mat, in seller mode, has 4 arrow buttons and 5 square buttons and 16 slots divided into 2 groups.
The bigger arrows switch between trades, the smaller ones switch between subtrades, the New Trade button creates a new trade, the Add Custom Trade button is currently unused, the Delete Trade button deletes the current trade, the Delete SubTrade button deletes the current subtrade and Trade Info button shows what is traded for what. The slots on the left are slots for thing that the Trade-O-Mat buys and slots on the right are what it sells.

The trade is created as follows: first, the New Trade is clicked. Next, either the Use Money button is clicked, which makes it a for-coins trade, and the coin amount is set up, or the items that are traded for are added. Then, the items/fluids/energy that is traded is setup on the right. At this point, the trade is basically created, but it's also possible to add a subtrade by clicking an arrow button on top.
It's also possible to setup trade cap per player or delay between trades. If both are used at the same time, the trade cap resets after the delay.

Buying

The basic Trade-O-Mat, in buying mode, has 4 arrow buttons, which are the same as in selling mode, the Trade button, which performs the trade if possible, the ShowHover Items button, which switches view of items to be traded for and the Trade Info and Trade Requirements buttons which show trade data. It also has Stock side window, which shows how many times the current trade can be finished, and the Trade Count side window which allows buying or selling multiple times at once.
To trade, dump all items to sell on the left side, choose the amount to sell in the Trade Count, put cells or batteries on the right if it's a Fluid- or Energy-O-Mat, press Trade button and pick the spoils.

The buying mode can be forced in your own Trade-O-Mats by right-clicking them while holding side inventory key (C by default).