How many veriable can use to voltage measurement?

[pramodpansare]

emon1.voltage(A0, vCalibration,1,7); emon2.voltage(A1, vCalibration,1,7); emon3.voltage(A2, vCalibration,1,7);

How many veriable limits for use different voltage?

When I use three veriable that's work fine but when I use forth veriable then it's not work... Example...

emon1.voltage(A0, vCalibration,1,7); emon2.voltage(A1, vCalibration,1,7); emon3.voltage(A2, vCalibration,1,7); emon4.voltage(A3, vCalibration,1,7);