Detcon 6400-N4X - Manual (Page 8)

1600/6400-N4X
1600/6400-N4X- Instruction Manual Rev. 1.1 Page 4 of 38
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 3-3.5Amps accumulative for all I/O modules and sensors attached to the
controller. (I.E. if there are 8 modules within the enclosure that have an accumulative current draw of 2Amps,
the sensors or I/O modules connected to the output 24VDC should not exceed 1.5Amps.) Refer to each
module and sensor manual for maximum expected current draw from each.
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 can be connected to a PLC, PC/HMI, DCS, or other
Modbus™ master polling serial communications device, refer to Section 7.0 Secondary Modbus™ Port.
Optionally, (the RS-485 output is standard, but can be replaced with the optional RS-232) connect the RS-232
output wiring to the D-sub connector located on the optional RS-232 Serial Communications PCB. (Refer to
Figure 4.) Use standard RS-232 cable and D-Sub connector. This serial output may be connected to a PC or
external serial printer.
No Comm
C NO NC
Fault Relay PCB
J1
Serial Communications
Primary
PCB
S
B
A A
B
S
Secondary
J3 J7
RS-232
Serial Communications
RS-485
PCB
S B A J3
(Optional) RS-232
RS-485
Rel
a
y
J2
500-003053-001 500-003054-000
500-005081-000 RS-485
Input Output
Port Port Input Port
Output Port
are brought out to the
Relay Contact connections
Terminal Block via J1
Figure 4 No Comm. Fault Relay and Serial Communications PCB’s
The No Communications Fault Relay is connected to a set of Terminal Blocks on the din-Rail (Figure 5 and
Figure 4.) The Terminal Blocks are labeled “NO COMM” “C”, “NO” and “NC”. The No Comm. Fault Relay
PCB, mounted on the back of the controller PCB, will de-energize the on board relay in the event there is a
‘No Communication Fault’ condition with any activated device. A ‘No Communication Fault’ condition will
‘short’ the common and normally closed contacts and create an open between the normally open and common
relay contacts of the on-board relay. This is required for fail-safe operation. There is a two-minute delay
before any active device will trigger a no communication condition.
The unit includes an Alarm Reset Switch that is mounted on the left side of the enclosure. A set of Terminal
Blocks is supplied for the connection of a Remote Alarm Reset Switch that can be mounted anywhere outside
the unit. The Remote Alarm Reset incorporates a set of normally closed contacts that cause the unit to reset
the Alarms when contact is broken. To install a Remote Reset Switch the jumper between terminal blocks 4
and 5 (labeled “Remote Reset”) must be removed and the switch wired to these terminals. Connect only a
normally closed switch to these terminal blocks. If more than one switch is to be connected, the switches must
be connected in series.
NOTE: The Remote Alarm Reset switch should be a ‘Normally Closed’ Switch and should be wired as
such. Failure to wire the switch correctly will cause the Enclosure Alarm Reset and all subsequently
connected Remote Alarm Reset Switches to be non operational.