ePAQ-9410 / ePAQ-
9420 User’s Guide UG-1071
Copyright © 2017 QEI
Communications Ports
13
Connector Pinout :
Connections for J2B, J2C, and J2D are identical to those listed in the table above for J2A.
6.2.2 Redundancy Capability:
The RS232/RS485 ports are all tri-stateable for redundancy capability between two ePAQ-
9410/9420 units. Redundan
cy is accomplished by asserting the “Comm Port Disable” input line
located on ethernet copper port J12C pin 8.
Additionally, the input disable line is driven up to the Comm Port expander board in the ePAQ-
9420 (via a DIP switch), so that all comm ports in the ePAQ-9420 can be disabled.
Two other ethernet copper ports (J12B and J12D) have a “Disable Comm Ports” output pin. The
output pins are each driven independently by the ePAQ-94XX processor. They are for disabling
other ePAQ-94XX or eXP-9430 units.
6.2.3 Isolation/Surge protection
Each of the RS232/RS485 communications ports is isolated from logic common (1KVdc Isolation).
Surge protection is provided using TVS clamping devices that clamp the lines of each
communication port to its’ own isolated common.
6.2.4 RS-485 Termination
RS-485 termination resistance is built-in to each port. Termination resistors are high value (3.9K)
to allow RS-485 ports from multiple ePAQ-9420 units to be placed in parallel.
RJ45 PIN #
Signal Type
Signal Name
J2A-1
RS-232
RTS (Request to Send)
J2A-2
RS-232
CTS (Clear to Send)
J2A-3
RS-232
TXD (Transmitted Data)
J2A-4
RS-232
RXD (Received Data)
J2A-5
RS-232
COM
J2A-6
RS-485
COM
J2A-7
RS-485
B-
J2A-8
RS-485
A+
