Each channel on a VC2124 voltage-to-current converter can output up to 100 mA. Any number or channels can be connected in parallel to achieve higher current output. Here is an example of connecting 5 channels in parallel, which requires three VC2124s:
The +/-10V output of the RMC is connected to all 5 channels. The Out pins of the VC2124’s are all connected together and connect to one side of the load resistor. A Cmn pin from each VC2124 are connected together and connect to the other side of the load resistor (the two Cmn pins on each VC2124 are internally connected).
It is important to make sure the load resistance is low enough that the RMC can drive the current. The VC2124 datasheet lists the maximum output voltages for each current range. Typically, when paralleling outputs, you will choose the 100mA range on each converter. This means the maximum guaranteed output voltage is 8.0 V. The load resistance should be low enough so that the maximum current output will not require a driving voltage greater than 8.0 V.
In this example, with a maximum of 500 mA output, the load resistance must be less than 8.0 V / 0.5 A = 16 ohms.