Toshiba nv Series - C.2 AC Input Modules

C.2 AC Input Modules
Unified Controller nv series type2 light Controller Unit Instruction Manual
115
C.2
AC Input Modules
(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) If the AC output type sensor or the like is connected, current higher than the
maximum OFF voltage may remain between the input terminals due to the
leakage current generated at sensor OFF time. If this occurs, input OFF may be
unable to be read although the sensor is OFF. In this case, install a bleeder
resistor between the input terminals to lower the input impedance.
V
入力モジュール
R
ブリーダ抵抗 交流出力型センタ
OFF 時漏れ電流
Figure C-6 Connecting the AC input
(Example of selecting bleeder resistor R)
Input module IN956
Input impedance approx. 8 kΩ (50 Hz)
OFF voltage 20 VAC
Input voltage = 100 VAC (50 Hz)
Suppose the voltage between the input terminals is 35 VAC at OFF time when no
bleeder resistor is installed. Let R [kΩ] be the resistance of the bleeder resistor to
be selected. Let P [W] be the wattage. The following is satisfied in this case:
8[k Ω ] × R
8[k Ω ] ＋ R
× ＜ 20[V]
35[V]
8[k Ω ]
Hence,
R ＜ 11 [k Ω ] → R = 10 [k Ω ]
AC output type center
Bleeder resistor
Input module
Leakage current
at OFF time