External Contact Point Inputs - Magnescale LY71 Handbuch

3-3. External contact point inputs

Input circuit for external input signals
• When using external input, connect the signal to the external input terminal for 10 ms or more (common
terminal). When inputting an external signal again, ensure an OFF time of 70 ms or more.
• Use a shielded cable for the connecting cable, and connect the shielding to the I/O connector shell. In
addition, connect COM separately from the shielding. (The switches and shielded cable should be prepared
separately by the customer.)
•
Input circuit for general-purpose input,
external reset and external preset value call
(preset recall)
<External power supply required>
(Note: +5 V can also be used)
To internal circuits
470 1 kΩ
+
4.7 µF/50 V
Input circuit delay time
When an input signal is input, the input circuit causes a delay time until that signal is transmitted to the
internal circuits. Note that this delay time differs greatly according to the input circuit operating voltage.
(Example) When operated at +24 V, the delay time until the signal is transmitted to the internal circuits is
approximately 350 µs.
The process time after the signal is transmitted to the internal circuits until operation is actually performed
differs according to the operating conditions. When not using expansion units, this takes at least 5 ms (min.).
This time becomes longer when expansion units are connected.
The delay time is greatly reduced by not connecting portion 1 in the "Input circuit for general-purpose
input, external reset and external preset value call (preset recall)" circuit drawing above. However, in this
case noise or other factors can easily cause misoperation. Therefore, be sure to take noise countermeasures
when not connecting portion 1.
When 1 is not connected
When using +24 V, the delay time is approximately 3 µs.
LY71
Apply +24 V
(or +12 V)
Vcc
Pin 1
Power supply
Input signal
Input signal
Pin 6
Switch
circuit
GND
COM
1
Pin 9
Example connected
circuits
•
Input signal timing
70 ms or more
3. Installation and Connection
10 ms
or more
9
(E)