5
Disclaimer
The information contained in this document is
subject to change without notice. Precision Digital
Corporation makes no representations or
warranties with respect to the contents hereof;
and specifically disclaims any implied warranties
of merchantability or fitness for a particular
purpose.
•Read complete instructions prior to installation
and operation of the meter.
•Risk of electric shock or personal injury.
•This product is not recommended for life support
applications or applications where
malfunctioning could result in personal injury or
property loss. Anyone using this product for
such applications does so at their own risk.
Precision Digital Corporation shall not be held
liable for damages resulting from such improper
use.
•The term “discrete” is sometimes used in this
document to refer to digital inputs and outputs,
where the value is either 0 or 1 (Logic Low or
High).
•When referencing Modbus, this manual uses the
terms “Client” to refer to what was previously
called “Master” and “Server” to refer to what was
previously called “Slave”.
WARNING
Cancer and Reproductive Harm - www.P65Warnings.ca.gov
Limited Warranty
Precision Digital Corporation warrants this
product against defects in material or
workmanship for the specified period under
“Specifications” from the date of shipment from
the factory. Precision Digital’s liability under this
limited warranty shall not exceed the purchase
value, repair, or replacement of the defective unit.
See Warranty Information and Terms &
Conditions on www.predig.com for complete
details.
Registered Trademarks
Modbus®is a registered trademark of Schneider
Electric. All other trademarks mentioned in this
document are the property of their respective
owners.
© 2023 Precision Digital Corporation.
All rights reserved.
Introduction
In its most basic form,the PDW90 consists of field units
(up to 32) that accept 4-20 mA signals and transmits
them wirelessly to a base station. The primary ad-
vantage of this system is how simple and economical it
is to get multiple signals (not just 4-20 mA, also discrete
(digital) and Modbus) from where you have them to
where you need them –all without having to run wires!
The wireless communication between the field units and
the base station is bi-directional. That means you can
send 4-20 mA, discrete and Modbus signals from the
field units to the base station and also send completely
different 4-20 mA, discrete and Modbus signals from the
base station to the field units. For instance, the field unit
could send a 4-20 mA signal to the base station corre-
sponding to the level in a tank and the base station could
send a 4-20 mA signal to the field unit to control a valve.
Field units are also equipped with four digital I/O that can
each be independently programmed as an input or an
output. A Loss of Signal warning is also availableby con-
necting devices to the G and LS screw terminals.
To indicate alarm situations in the field, the field unit can
be equipped with an optional, field installable, two relays
module.These relays are rated Form A (SPST) 5A and
are controlled by the digital outputs on the base station.
The base stations are available in configurations for 2, 6,
or 16 I/O slots for a variety of field installable I/O
modules. The available I/O modules are:
•Dual Analog Input
•Dual Analog Output
•Dual Relay Output
•Four Digital I/O
The specified range between the base station and
field units is 1 mile line-of-sight outdoor and 500 feet
indoor and repeaters are available to extend the
range. A low-cost wireless survey tool, Model PDA10,
is available to test the signal strength of your
application before you buy. And if the PDW90 system
does not work in your application, you can return it for
full credit!
