Is the "Card Reader Power" specified in the datasheet per reader input or the controller total?
It does not define on the datasheet if the reader power specified is for each reader input or the controller total.
The reader current available specified on the ACXII datasheet is for each of the reader inputs.
The jumpers on the board are used to define if each channel is supplying +12VDC or +5VDC.
Each of the 4 reader inputs on an ACX5720 or the 8 reader inputs on an ACX5740 can supply the following:
120mA @ +5VDC
180mA @ +12VDC
If a reader is used that has a peak (Maximum) current consumption that exceeds this then it must be powered from a separate external power supply.