Dc Input Modules - Toshiba Vm Series Instruction Manual

Appendix C Notes on Applying the I/O Modules
C.1 DC Input Modules
120
6F8C1645
(1) The condition for reading the input signal ON/OFF changes completely is
either of the following:
[Input ON time] = [OFF-to-ON response time] + [Input read cycle]
[Input OFF time] = [ON-to-OFF response time] + [Input read cycle]
The input read cycle is the scanning cycle for batch input/output.
Alternatively, it is the direct input instruction execution cycle if a direct input
instruction is used.
(2) For some external contacts, the reliability of contact may be unable to be
guaranteed with the input current of the module. In this case, install a
bleeder resistor between the input and common so that dummy current can
flow.
Contact
I
V
Figure.C.1-1
(Example of selecting bleeder resistor R)
Input voltage V = 24 VDC
Input module DI934 (5.2 mA / 24VDC)
When you want to set the contact currect to 50mA,
Resistance of bleeder resistor
Wattage of bleeder resistor
Input module
V
R=
I-I
I
1
1
V 2
Wattage P >
R
I
2
DC input connection
24[V]
R =
50[mA] – 5.2[mA]
2
(24[V])
P =
(536[Ω])
x (2.5~3)
= 536[Ω]
× (2.5～3) ≒ 3[W]