User Manual
Page 2
1. INTRODUCTION
The DX Box is designed to connect two
load/unload air compressors to a system
management unit, using a 2-wire RS485 data
cable up to 500m (1650ft) in length.
The DX Box is designed specifically to ‘group’
two compressors together as a single
coherent unit. The system management unit
will detect and manipulate the two
compressors as a single multiple step or
variable output compressor unit.
The DX Box is able to manipulate two identical
capacity compressors to form a single ‘group’
that will act in an identical manner as a 3-step
compressor. The DX Box is also able to
manipulate two differential capacity
compressors providing demand matched
control and sequence to form a single ‘group’
that will act in an identical manner as a
variable stepping output, compressor.
This functionality provides the ability to:
a) Group two adjacent air compressors
together as a single coherent unit.
b) Combine two similar capacity
compressors together to form a three-
step variable output group acting as a
single coherent variable output unit.
c) Take advantage of a small or minimal
capacity compressor, grouped
together with a medium or higher
capacity compressor, to form a high
capacity, variable output, group acting
as a single variable output ‘top-up’
compressor.
d) Exceed the maximum compressor
control capability of a system
management unit by combining
compressors together as one.
Two single pressure switch control type air
compressors can be connected to the DX Box
using a 6-wire cable and a compressor
interface PCB (i-PCB). The ‘i-PCB’
connections are identical to an system
management unit.
The DX Box also provides optional ‘local
pressure sensor’ connections. The
compressor delivery pressures, local system
pressure and air treatment differential
pressures can be displayed. The monitored
local pressure is available on the system
network and can be utilised by an system
management unit for advanced pressure
related functions.
Any number of DX Boxes can be connected to
an system management unit as long as the
total number of single compressors and/or
groups does not exceed the total number of
compressors for the system management unit
model.
1.1 Management System Connectivity
1
2
#1
DX Box
3
#2
The DX Box connects to an ystem
management unit using an industrial two wire
RS485 data network (Multi485).
1.2 Basic Function
The DX Box is a ‘Duel unit eXtension’ to a
system management unit providing the ability
to group two individual air compressors
together in to one duel ‘group’ acting as a
single coherent unit.
The DX Box provides additional ‘i-PCB’
connectivity.
The DX Box can also be used to provide ‘i-
PCB’ connectivity at a remote location beyond
the maximum distance specification of direct
system management unit connection.
1.3 Operation
2.3.1 Timer Rotation Mode (Tr)
#1
#2
50%
50% = 100%
1
A B
2
B A
A
B
Timer Rotation should be used when the two
compressors have the same (50:50), or very
similar, output capacity. The DX Box will
assign one compressor as ‘Duty’ and the other
as ‘Standby’. The duty compressor will always
be loaded first and the standby used as and
when required to meet demand. The duty and
standby assignment will be changed at every
‘Interval Time’ (adjustable).
