Watlow Optimizing Your Process System with the Series 988 Controller - Manual (Page 48)

Optimizing Your Process System with the WATLOW Series 988
Standard Features
5.8
TL TL W WA
PROCESS
L1 L2 L3 L4
DEV
% OUT DISPLAY
MODE
AUTO
MAN
SERIES 988
TL TL W WA
PROCESS
L1 L2 L3 L4
DEV
% OUT DISPLAY
MODE
AUTO
MAN
SERIES 988
TL TL W WA
PROCESS
L1 L2 L3 L4
DEV
% OUT DISPLAY
MODE
AUTO
MAN
SERIES 988
Transmitter Power Supply
Overview
In an electrically noisy environment or when
you have to use a long sensor lead, you may
need to use a transmitter to convert the sensor
signal to a 4-20mA signal. Normally you would
have to buy and install a separate power
supply for the transmitter or for other signal
conditioning devices, but you can order a
Series 988 with a 30mA power supply as one of its outputs. The factory sets the power supply
voltage to 20VDC, but you can use DIP
switches to change it to 5 or 12VDC as well.
Requirements
A transmitter power supply can be ordered for
output 2, 3 or 4.
Heater Controller Evaporator Controller Pump Controller
Control Room
Sample Application
An engineer at a food processing plant needs to control several processes from
a central control room, which is more than 100 feet away from some of the
machines being controlled. Because of the distance and the noisy electrical
environment, thermocouples cannot provide dependable readings.
The engineer has installed several Series 988 controllers with power supplies
matched to a variety of transducers. DIP switch settings configure the output
voltages for 5, 12 or 20VDC.
output 4
output 1 input 1 output 1
output 3
humidity transmitter
humidity transmitter pwr
input 1 input 1 output 1
output 2
process flow transmitter
process flow transmitter power
pump
evaporator
RTD transmitter
heater
RTD transmitter power