USB to Serial Converters Manual
Version 2.1
Document Reference No.: CP_000032 Clearance No.: CP#022
Copyright © Connective Peripherals Pte Ltd
24
Wiring Diagrams
The following diagram shows an RS-485 full-duplex bus. The ES-U-xxxx-x has a built-in resistor for
terminating its RxD +/- input, which can be enabled using a jumper. The Tx +/- lines which are outputs
from the ES-U-xxxx-x would be terminated at the receiver at the other end of the bus as shown. Twisted
pair wires are required for each signal pair.
Figure 15 - RS-485 Full Duplex Wiring
5.5
5V Power Output (ES-U-1002-M only)
2-way Terminal Block
Table 24 shows the pin-out of the 2-way terminal block on the ES-U-1002-M converter. This provides 5V
at up to 150mA for external devices. This power is supplied by the USB port of the computer.
Pin Number
Pin Type
Description
1
Output
5V output at up to 150mA
2
Ground
Ground
Table 24- 5V Power Output
RS-485 Device
ES-U-xxxx-x
RxD+
TxD+
RxD-
TxD-
TxD+
RxD+
TxD-
RxD-
GND
GND
