Figure 5 interface wiring terminals – Detcon 1600A-N1P User Manual
Page 9
1600A-N1P
Where applicable, 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 on 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 3.0Amps.) Refer to each
module and sensor manual for maximum expected current draw from each device.
C
NO
NC
A
B
+
RS-485 VDC
A
B
RS-485
Primary
Second
Out
RESET
Figure 5 Interface 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 the warranty will be void. Modules and
sensors attached to the unit that exceed this power rating should be powered by an external power
supply capable of handling the extended load.
The secondary serial RS-485 port from the controller is connected to a set of Terminal Blocks on the DIN Rail
(Figure 5). 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 Section 5.5
1600A-N1P Instruction Manual
Rev. 0.1
Page 5 of 40