ADLINK PCI-7251 - Manual (Page 43)

Operation Theory 35
4.2 Using Isolated Input
The PCI-7250 (or PCI-7251) contains 8 identical opto-isolated
control input channels. The circuit diagram of the differential input
channel is shown below.
Figure 4-3: PCI-7250 Differential Input Circuit
The digital input is first routed through a photo-coupler (PC-814),
which is shown in the following diagram.
The cPCI-7252 contains 16 identical opto-isolated control input
channels. The circuit diagram of the differential input signals of
channel number 0-7 are the same as of the PCI-7250. While the
input signals for channel numbers 8-15 are isolated inputs, the
connection is not polarity sensitive whether AC or DC voltage is
used.
Figure 4-4: cPCI-7252 Isolated Input Circuit
V
IN
2.2k
Ω
Ri
PC-814
(opto-isolator)
I
F
DInH
DInL
V
IN
1.2k
Ω
Ri
PC-814
(opto-isolator)
I
F
DInH
IGND