Download PWM-C Pulse Width Modulation to Current Transducers

P R O D U C T
D A T A
PWM-C Pulse Width Modulation to Current Transducers
CSI’s Model PWM-C1 and PWM-C2 transducers provide
a 4 to 20 mA and 0 to 20 mA output, respectively,
proportional to the duration of the pulse input.
PWM-C Features
• Higher resolution than 8 bid AO
• 4 – 20 mA or 0 – 20 mA
• Dual range
0.1 – 5.2 seconds
0.1 – 25.6 seconds
• Anti-wraparound protection
Physical Description
Both the PWM-C1 and PWM-C2 are provided with a simple 3-wire
electrical connection, for control and 2-wire electrical connection to
the controlled device. The PWM-C1 and PWM-C2 are contained on a
single integrated circuit board designed for panel mounting using
the supplied snap-track mounting rail.
Electrical connections are terminated on a 5-position terminal strip
on the bottom edge of the card for easy access. Power and clock status is displayed via a green LED and presence of a PWM signal from
the DDC controller is indicated via a red LED.
The PWM-C1 and PWM-C2 may be powered by either a 24-volt
AC or DC source to eliminate the requirement for a special
transformer or power supply for a single transducer. Controller
Red LED indicates
detection of pulse input.
5 SEC/25 SEC
PULSE WIDTH
SELECTION
Green flashing LED
indicates power and
clock rate.
INPUT
5 J2 25
SEC • • • SEC
R27 D5
•
••
•
Remove R27 for
MR 0r I/SITE Triac
input. Remove both
for UC Triac input.
POWER
CLOCK
COMMON (GROUND)
OUTPUT TO DEVICE
UNDER CONTROL
ANALOG INPUT
+
PDS 103 9/94
V G I O G
1 2 3 4 5
–
24V supply polarity
indication applies if
DC supply is used.
CONTROL UNIT
+24V
–GND
Pulse width
modulated output
using normally
open relay
contact or open
collector
transistor or
Triac.
Common (Ground)
connection when
Triac or transistor
output is used.
Control Systems
International
®
P R O D U C T
Control Systems International
D A T A
PWM-C Pulse Width Modulator to Current Transducers
MODEL NUMBER
DESCRIPTION
COMMENTS
PWM-C1
Current Transducer, Pulse Width Input (5.2 or 25.6
seconds), 4 – 20 mA Output
Current Transducer, Pulse Width Input (5.2 or 25.6
seconds), 0 – 20 mA Output
With Snap-Track
PWM-C2
pulse inputs may be created by mechanical dry contacts, solid state
open collector transistors (NPN) or triacs as shown in the wiring
diagram. If the input is from a Unitary Controller Triac (Triac to
ground), remove resistor R10 and diode D2 as shown on diagram.If
the input is from a Universal MicroRegulator or I/SITE I/O
Controller Triac, remove resistor R10 only.
PWM-C1 and PWM-C2 input full range time is user selectable
between two jumper selectable ranges: 0.1 to 5.2 second pulse input
or 0.1 to 25.6 second pulse input, to provide rapid loop response time
when required. The time base is jumper selectable via a plug-on
jumper labeled J2. An input pulse of less than 0.1 second duration
will be rejected by the transducer and no change will occur in the
input.
The PWM-C1 and PWM-C2 transducers internally limit the
maximum input signal to a full scale range of 255 counts and does
not allow “wraparound” on pulses of longer duration than the
specified or selected maximum. Upon power initialization the
PWM-C1 or PWM-C2 forces the output to 0% of scale value until
receipt of the first pulse input from the DDC controller.
With Snap-Track
POWER
SUPPLY VOLTAGE: 24 to 35 Vdc @ 75 mA; 18 to 28 Vac @ 150 mA
50/60 Hz
CSI Transducer Conversion Coefficients
Transducer
PWM-C1
PWM-C1
PWM-C2
PWM-C2
Resolution
Counts
0-255
0-255
0-255
0-255
Input Range
(seconds)
0.1-5.2
0.1-25.6
0.1-5.2
0.1-25.6
Source
Range (FS)
0-100%
0-100%
0-100%
0-100%
M (Slope)
0.19608
0.03922
0.19608
0.03922
B (Intercept)
–1.96078
–0.39216
–1.96078
–0.39216
Output Range
(milli amps)
4-20
4-20
0-20
0-20
Specifications:
PHYSICAL DESCRIPTION
PCB DIMENSIONS: 4'L x 3.25"W (10.2 cm x 8.25 cm)
SNAP-TRACK DIMENSIONS: 4"L x 3.5"W (10.2 cm x 8.9 cm)
TRANSDUCER
INPUT PULSE DURATION: 0.1 to 25.6 seconds or 0.1 to 5.2
seconds
INPUT PULSE RESOLUTION: 0.4%
INPUT INTERFACE: Dry contact, triac or open collector transistor
INPUT EXCITATION VOLTAGE: +15 Vdc (continued or pulsed)
OUTPUT CURRENT (PWM-C1): 4 to 20 mA
OUTPUT CURRENT (PWM-C2): 0 to 20 mA
OUTPUT EXCITATION VOLTAGE: 13.5 Vdc (675 ohm max loop
resistance)
LINEARITY: 1% full scale
ENVIRONMENTAL
OPERATING TEMPERATURE: 32° to 132°F(0° to 50°C)
HUMIDITY REQUIREMENTS: 10% to 90% (non-condensing)
Information in this publication is based on specifications believed correct at the time of publication. The
right is reserved to make changes in specifications and models as design improvements are introduced.
PDS 103 9/94
CSI Group Headquarters
PAN-AMERICAN MARKET
CSI CONTROL SYSTEMS INTERNATIONAL
1625 W. Crosby Rd., Suite 100
Carrollton, Texas 75006
Phone: 972-323-1111, Fax: 972-242-0026
EUROPEAN COMMUNITY MARKET
CSI Europe
Unit B3, Armstrong Mall – Southwood,
FARNBOROUGH GU14 ONR United Kingdom
Phone: 44 1252 370900, Fax: 44 1252 372470
ASIA-PACIFIC MARKET
CSI Pacific
36 Hasler Rd.
Osborne Park, Western Australia 6017
Phone: 61-9-244 2799, Fax: 61-9-244 4335
www.control systems. com
Control Systems
International
®