DDS EX
Explosion-Proof Transmitter and Controller Instruction Manual
5
Introduction
The
DSS EX
is a fully FM, CSA, ATEX, and IECEx approved explosion-proof product. I
t can be
programmed as a Modbus RTU Master, Slave, or Snooper. It is capable of scanning up to 16
variables generated by any Modbus device, which makes it ideal for tank level monitoring and
control. Its superluminous LED digits make it easily readable in smoke, dust, fog, and, with the
optional SunBright® display, even direct sunlight.
As a master, the DSS EX can read up to 16 slave devices, scales the data from each, displays
the result, and operates the internal relays and 4-20 mA output. The DSS EX in Master mode is
capable of polling up to 16 process variables (PVs); it displays all the enabled PVs in sequence,
at a user programmable scan rate; it also allows other transmitter and controllers in Snooper
mode to read any of the variables being polled by the master. As a snooper, the it listens to the
Modbus traffic and picks up a specific register or registers being polled by a master device from
a specific slave device and processes the data being read. As a slave, it is controlled by a
master device. The data sent to it by the master is scaled, displayed, and used to operate the
relays and 4-20 mA output.
Data is displayed on an adjustable intensity, dual-line, six-digit display. Its superluminous LED
digits make it easily readable in smoke, dust, fog, and direct sunlight. The upper display is a 0.6
inch, seven-segment LED display, while the lower display digit height is 0.46 inches. The DSS
EX can be powered from 85-265 VAC or 12-36 VDC. It is available with up to 4 internal relays
and 4 digital inputs/outputs.
The DSS EX comes equipped with dual analog input channels (4-20 mA and/or 0-10 VDC) for
use in Master Mode. These can be assigned to mA or volts by mapping a PV to the internal
scanner addresses 256-259, depending on the desired function.
Various math functions may be applied to the Modbus and analog inputs including addition,
difference, absolute difference, average, weighted average, multiplication, division, minimum,
maximum, draw, ratio, and concentration. This is in addition to the signal input conditioning
functions (linear, square root, programmable exponent, or round horizontal tank calculations).
The displays, relays, and the analog outputs may be assigned to PVs or to math channels C1,
C2, C3, or C4. The digital inputs/outputs can be custom-programmed for specific operations. A
digital input (F4) is standard.
Free ScanView software allows the DSS EX to be programmed directly from a PC using the
onboard USB connection. Configure multiple scanners, conveniently monitor critical
information, and Datalog right from a PC with ease, further increasing plant efficiency.
