Toshiba T2N - Manual (Page 66)

3.Application Precautions for I/O Modules
User’s manual 51
(1) Minimum ON/OFF time of input signal
The conditions for guaranteed reading of the ON/OFF states of the input
signal are:
Input ON time ON delay time + 1 scan time
Input OFF time OFF delay time + 1 scan time
Therefore, be sure to use longer times than these for the ON/OFF times of
the input signal.
(2) There are some contacts for which the reliability of contact cannot be
guaranteed at the specified input current, depending on the contacts. In
such cases, install an external bleeder resistor and pass a dummy current.
Input Module
I
2
V
I I
1 R=
Wattage P> X 3
V
I
−
I
1
V
2
R
(3) The following are examples of connection with transistor output equipment
(such as proximity switches).
Input Module
Input Module
•
NPN open collector type (+common)
•
PNP open collector type (-common)
(4) When using a switch with an LED, if the LED-lighting current flows even
when the switch is OFF, it sometimes cannot be recognised as OFF. In
this case install bleeder resistor R and decrease the input impedance.
LED
R
r
Input module
3.1
Input Modules
Application Precautions