P4 connectivity for DaqBook/2000 “AEX” devices is as follows:
• One end of a CA-195 cable connects to the DaqBook/2000 “AEX” device’s 100-pin P4
connector. Note that the CA-195 cable has two P4 connectors.
• The other end of the CA-195 cable connects to a DBK200 Series adapter board [or adapter
module] for 100-pin to 37-pin adaptations, e.g., P4-to-P1, P2, P3; but not necessarily all three.
• The DBK200 Series adapter connects to one or more CA-37-x ribbon cables, where “x”
indicates the number of expansion devices that can be connected. For example, in addition to
providing a DB37 connector to interface with the primary data acquisition device, a CA-37-3
cable includes three additional DB37 connectors. These provide a means of adding three
DBKs to one port. Use of a CA-37-16 cable will allow up to 16 DBKs to be added.
• The CA-37-x cable connects to expansion DBKs, in accordance with port type. For example,
Analog DBKs to port P1, Digital DBKs to port P2, and passive DBKs to port P3.
There are two ways to connect a DBK option to a DaqBook/2000 “AEX” device. The first
method is preferable, as it introduces less noise.
Preferred Method – (a) Connect a CA-37-x cable to the appropriate DB37 connector
[P1, P2, or P3] on the DaqBook/2000 Series device. (b) Connect the
free end of the cable to the DBK card or module.
Optional Method – (a) Connect a CA-195-x cable to the P4 connector on the
DaqBook/2000 Series device. (b) Connect the free end of the cable
to a DBK200 Series device. (c) Connect the DBK option to the
DBK200 Series device, as applicable.
The primary reason that less noise is seen in the “preferred” method is that a
DaqBook/2000 “AEX” device’s P1 connector pertains only to analog acquisition signals
and the P2 connector pertains only to digital I/O. This provides a strong degree of
isolation between the two signal types. However, in the case of a CA-195-x cable
connected to P4, digital and analog signals co-exist in one cable.
If you need to use the P4 connection method, use of the 8-inch ribbon cable (CA-195-1)
will result in the lowest level of crosstalk [for that method].
The CE Cable Kit, p/n CA-209D, may be required for systems that require a P4 cable
length of 3 feet. The CA-209D kit includes a shielded version of the CA-195 cable, two
grounding pigtails, and associated cable clamps. When properly connected, the shielded
cable provides greater immunity to noise. The CE Compliance chapter includes details.
pg. 8, DBK Basics 967794 Daq Systems