Antona Corporation
10
(818)783-4299
Interface Wiring
Terminal Block Wiring – T adapter version
The
ANC-6185
T
has letter designations on the edge of the PCB in front of the 6-pin
terminal block which identify the pin interface wiring. The designations read correctly when
JP5/6 are set for MASTER. See figure 1 above along the right hand side of the adapter and the
table below for the designation definitions:
Terminal Pin # Marking on PCB
Function
6
G
Power and signal ground
5
R-
RC-, Receive minus to adapter
4
R+
RC+, Receive plus to adapter
3
T-
TX-, Transmit minus from adapter
2
T+
TX+, Transmit plus from adapter
1
V
ExDC Voltage to adapter
RJ-45 Wiring – R adapter version
Wiring to the RJ-45 ANC-6185
R
adapter version for the transmit and receive lines follow
the same wiring as an ethernet CAT-5 type cable
– but the adapter is not meant to ethernet type
signals
. The signal lines were placed to match ethernet wiring in order for the designer to use
low-cost ready-made cables or installed cabling.
RJ-45 Pin #
Function
8 -not
used-
7 -not
used-
6
RC-, Receive minus to adapter
5
Power and signal ground
4
ExDC Voltage to adapter
3
RC+, Receive plus to adapter
2
TX-, Transmit minus from adapter
1
TX+, Transmit plus from adapter
RS-485 Two and Four Wire Interfacing
2-wire
One of the key features of using a controlled transmit adapter like the ANC-6185 is for
applications using multidrop 2-wire interfacing with other RS-485 type equipment. Usually a two wire
interface with multiple peripherals uses a ‘polled-response’ half-duplex software protocol where each
device has a unique device code. Generally, this requires externally powering of the adapter, but for
short cable runs to non-terminated equipment operating at medium baud rates (like 9600 or less) an
external power supply may not be needed. The designer should use twisted pair wire with an impedance
of 100 to 120 ohms. Plain old low-cost CAT-5 UTP (Unshielded Twisted Pair) wire works fine. The user
must set JP8/9 vertical (TX+ to RC+, TX- to RC-) inside the adapter. The 2 conductor cable which
connects to the outside world is then wired to the ANC-6185 adapter’s TX+ terminal (+DATA) and to TX-
(-DATA). Match TX+ to the +DATA, or +D, and TX- to –DATA, or –D, of the RS-485 compatible
peripheral. The photo 2 below shows a typical transmission and reception sequence over an RS-485 2-
wire interface using the ‘AutoXmit’ adapter feature. The top trace shows the data transmitted from the
ANC-6185 with a scope probe on the TX+/RC+ (+DATA) combined line. The 2
nd
group of noisy looking
characters is the response received from a remote device about 4 ms after the last character is sent
