
18
Signal Connections
3.2
Isolated Input Ports (LTC, INCOM)
There are 4 pairs of isolated input ports on PCI-8124. Each pair
has two terminals. One is INCOMx, and the other is LTCx.
Because the input port of the photo coupler utilized on PCI-8124 is
single-directional, LTC signal must be lower than INCOM signal.
When there is a differential voltage between LTCx and corre-
sponding INCOMx, the photo coupler will turn on immediately.
There is an internal resistor in the PCI-8124 circuit as figure shows
below. So it is not necessary to attach additional resistor con-
nected outside the PCI-8124. The forward current of input signal is
7.5mA to 12.5mA. The typical forward voltage is 1.65V, and the
maximum forward voltage is 1.9V. So users should calculate the
appropriate voltage applied on LTCx and INCOMx.
CN1 Pin No.
Name
Description
1
INCOM1
In1 Com
3
INCOM2
In2 Com
30
INCOM3
In3 Com
32
INCOM4
In4 Com
2
LTC1
Isolated Latch 1
4
LTC2
Isolated Latch 2
27
LTC3
Isolated Latch 3
29
LTC4
Isolated Latch 4
INCOMx
LTCx
Outside PCI-8124
inside PCI-8124
Max 30mA
2.2K
Ω
7.5mA to 12.5mA
Summary of Contents for PCI-8124
Page 5: ......
Page 17: ...8 Introduction ...
Page 30: ...Signal Connections 21 Outside PCI 8124 inside PCI 8124 TRGx 220Ω ...
Page 33: ...24 Signal Connections ...
Page 49: ...40 Operation Theory ...
Page 72: ...Function Library 63 I16 Enable Enable Disable linear set X 0 disable 1 enable ...
Page 83: ...74 Function Library ...