HP AD278A and AD279A PCI Multiplexer Support Guide, November 2008

Port Modules
A port module is an interface between the AD279A PCI MUX 64-port adapter and the RS-232
peripheral device. Table 1-6 lists the port modules that can be connected to the AD279A PCI
MUX 64-port adapter.
Table 1-6 Port Modules
Number of PortsInterfaceDescriptionProduct Number
16RS-232 RJ-45HP 16-port RS 232 RJ-45 port moduleAD280A
16RS-232 DB-25HP 16-port RS 232 DB-25 port moduleAD281A
Each AD279A PCI MUX 64-port adapter supports a maximum of four port modules (64 ports)
connected together. The RS-232 RJ45 port module (AD280A) and RS-232 DB25 port module
(AD281A) can be intermixed using an EBI cable. The DB25 connectors are male.
NOTE: The pin assignments on the RJ-45 ports are incompatible with the RJ-45 pin assignments
used on the older A6748A/A6749A PCI MUX products.
Cables used to connect port modules two, three, and four are known as EBI cables. Each EBI
cable is one feet (0.30480 metre) in length. The RJ45 and DB25 port modules use the same EBI
cable. The AD280A and the AD281A use the same power supply (AD280-2001A).
NOTE: The AD279A PCI MUX 64-port adapter can support 2 port modules or up to 32 port
configurations without the port module power supply. The port module power supply is required
on the third port module and the fourth port module or 33 through 64 port configurations.
Figure 1-3 shows a PCI MUX 16-port RS-232 RJ45 port module.
Figure 1-3 RS-232 RJ45 Port Module
Table 1-7 lists the metrics equivalent.
Table 1-7 Metrics Equivalent
CentimetreInches
30.48012
17.7807
5.7152.25
Figure 1-4 shows a PCI MUX 16-port RS-232 DB25 port module.
AD278A/AD279A PCI Multiplexer Components 11