3
Equinox ESP-2 MI Serial Hub Installation Guide
When RS-422 signalling is set, the receiver and transmitter are always enabled.
Pin Assignments
Table 3 lists the pin assignments for the ports’ DB-9 connectors. This information is also
provided on a label on the bottom of the unit.
Pin RS-232
RS-422
RS-485
1 DCD
RXD(+) N/C
2 RxD
RXD(-) N/C
3 TxD
TXD(+)
Data(+)
4 DTR
TXD(-) Data(-)
5 GND
GND GND
6 DSR
N/C
N/C
7 RTS
N/C
N/C
8 CTS
N/C
N/C
9 N/C
N/C
N/C
Not supported: RI, RS-422 RTS and CTS differential control signals
Table 3. Serial Port Pin Assignments
NOTE:
Unused pins (labeled N/C) should not have wires attached to them. Floating wires could
cause unbalanced noise, shorten overall distances and degrade performance.
Table 4 lists the pin assignments for the RJ-45 shielded Ethernet connector.
Pin Signal
1 Transmit
Data
+
2
Transmit Data -
3 Receive
Data
+
4 *
5 *
6
Receive Data -
7 *
8 *
* These pins are usually connected in a standard Ethernet CAT 5 cable. There is special termination
for those signals in the interface to eliminate any problems if they are connected.
Table 4. Ethernet Connector Pin Assignments
Electrical
The ESP-2 MI has two electrical power connectors on the front of the unit. These connectors
are labeled POWER 9-30VDC 4W. You may use either one of these connectors, but not both.
•
The unit ships with an external power adaptor. This adaptor includes a barrel plug that is
inserted into the leftmost power connector on the unit’s front panel.
