Mitsubishi Electric Melsec-Q172DCPU User Manual page 220

6 INSPECTION AND MAINTENANCE
(b) Calculate the connecting resistor value R as indicated below.
To satisfy the 0.9 [mA] OFF current of the Motion CPU, the resistor R to be
connected may be the one where 3.1 [mA] or more will flow.
I : Iz = Z(Input impedance): R
R
Iz
R 
× Z(Input impedance) =
I
R
R < 1625 [ ]
Assuming that resistor R is 1500 [ ], the power capacity W of resistor R is:
W = (Input voltage)
(c) The power capacity of the resistor selected is 3 to 5 times greater than the
actual current consumption. 1.5k [ ], 2 to 3 [W] resistor may therefore be
connected to the terminal in question.
0.9
3.1 × 5.6 × 10
2 2
÷ R = 26.4 ÷ 1500 = 0.464 [W]
6 - 31
3
= 1625[ ]