Detcon 1600A-N4X - Manual (Page 9)

1600A-N4X
1600A-N4X Instruction Manual Rev. 0.2 Page 5 of 38
4. Connect the RS-485 wiring from remotely located I/O devices to the terminals located on the Back Panel.
These terminals are labeled RS-485 “A” (+), “B” (–), and “Shld” (shield) for primary RS-485
communication (Figure 5). RS-485 wiring should consist of a two conductor, shielded twisted pair
(Belden cable P/N 9841 is recommended). Also available are two output terminal blocks to provide
24VDC to external RS-485 devices. This power should be used only to power remotely located I/O
modules and/or sensors, and should not exceed a total of 3 Amps accumulative for all I/O modules and
sensors attached to the controller. (I.E. if there are two modules mounted in the enclosure that have an
accumulative current draw of 0.5Amps, the sensors and/or I/O modules connected to the output 24VDC
should not exceed 2.5Amps.) Refer to each module and sensor manual for maximum expected current
draw from each device.
Part of
TB1
+
RS-485 VDC
Primary Out
A B
Figure 5 RS-485 wiring Terminals
WARNING: Do not attach more devices to the controller power supply than the power supply has the
capacity for, as damage may occur to the controller and will void the warranty. Modules and sensors
attached to the unit that exceed this 3Amp power rating should be powered by an external power
supply capable of handling the extended load.
5. The secondary serial RS-485 port from the controller is connected to a set of Terminal Blocks on the DIN
Rail (Figure 6). The Terminal Blocks are labeled Secondary “A, B & Shld” and can be connected to a
PLC, PC/HMI, DCS, or other Modbus™ master polling serial communications device, refer to Secondary
Modbus™ Port Section 5.5.
C
NO NC
A B
RS-485
Second
RESET
Part
of
TB1
Figure 6 Interface Wiring