Watlow CAS User Manual
CAS
User ’s Guide
Watlow Controls
1241 Bundy Blvd.
Winona, MN 55987
Customer Service
Phone: (800) 414-4299
Fax: (800) 445-8992
Technical Support
Phone: (507) 494-5656
Fax: (507) 452-4507
Email:
Part No. 21952-60. Revision 1.2
February 1996
wintechsupport@watlow.com
Copyright © 1996
Watlow Anafaze
Information in this manual is subject to change without notice. No part of this publication may be
reproduced, stored in a retrieval system, or transmitted in any form without written permission
from Watlow Anafaze.
Warranty
Watlow Anafaze, Incorporated warrants that the products furnished under this Agreement will be
free from defects in material and workmanship for a period of three years from the date of shipment. The customer shall provide notice of any defect to Watlow Anafaze within one week after the
Customer's discovery of such defect. The sole obligation and liability of Watlow Anafaze under this
warranty shall be to repair or replace, at its option and without cost to the Customer, the defective
product or part.
Upon request by Watlow Anafaze, Incorporated, the product or part claimed to be defective shall
immediately be returned at the Customer's expense to Watlow Anafaze. Replaced or repaired products or parts will be shipped to the Customer at the expense of Watlow Anafaze.
There shall be no warranty or liability for any products or parts that have been subject to misuse,
accident, negligence, failure of electric power or modification by the Customer without the written
approval of Watlow Anafaze. Final determination of warranty eligibility shall be made by Watlow
Anafaze. If a warranty claim is considered invalid for any reason, the Customer will be charged for
services performed and expenses incurred by Watlow Anafaze in handling and shipping the
returned unit.
If replacement parts are supplied or repairs made during the original warranty period, the warranty
period for the replacement or repaired part shall terminate with the termination of the warranty
period of the original product or part.
The foregoing warranty constitutes the sole liability of Watlow Anafaze and the customer's sole
remedy with respect to the products. It is in lieu of all other warranties, liabilities, and remedies.
Except as thus provided, Watlow Anafaze disclaims all warranties, express or implied, including
any warranty of merchantability or fitness for a particular purpose.
Please Note: External safety devices must be used with this equipment.
Contents
Contents
Introduction................................................................1
CAS Features ...................................................................... 3
Specifications...................................................................... 3
Analog Inputs................................................................ 3
Digital Inputs ................................................................ 4
Digital Outputs.............................................................. 4
System Digital Outputs................................................. 4
Miscellaneous Specifications.............................................. 5
Serial Interface .............................................................. 5
System Power Requirements ........................................ 5
Environmental Specifications ....................................... 5
Physical Dimensions..................................................... 5
Installation..................................................................7
Precautions and Warnings .................................................. 8
Recommended Tools .......................................................... 9
Panel Hole Cutters ........................................................ 9
Other Tools ................................................................... 9
CAS Mounting Procedure................................................... 10
Mounting Environment................................................. 10
TB-50 Mounting Instructions ............................................. 11
General Wiring Recommendations..................................... 13
Grounding ..................................................................... 14
Thermocouple Wiring................................................... 14
Input Wiring.................................................................. 15
Communications Wiring............................................... 15
Wiring: Noise Suppression ................................................. 16
Symptoms of RFI.......................................................... 16
Avoiding Noise Problems............................................. 16
General Wiring ................................................................... 17
Power Wiring and System Test .................................... 17
Outputs................................................................................ 19
Wiring Outputs ............................................................. 19
Alarm Output Connections ........................................... 21
Watchdog Timer ........................................................... 21
TB-50 Connections ....................................................... 22
Inputs .................................................................................. 23
Input Scaling ................................................................. 23
Scaling Values .............................................................. 24
CAS User’s Guide i
Contents
T/C Inputs ..................................................................... 26
Current Inputs ............................................................... 26
Voltage Inputs............................................................... 27
Unused Inputs ............................................................... 27
Back Terminal Block Connections ............................... 27
Serial Communications....................................................... 28
RS-232 Interface ........................................................... 28
RS-485 Interface ........................................................... 28
Using the CAS ............................................................33
Introduction......................................................................... 33
Front Panel.......................................................................... 34
Front Panel Keys........................................................... 34
Single Channel Display ...................................................... 36
Job Display ......................................................................... 37
Change Setpoint.................................................................. 38
Alarms................................................................................. 39
Setup ...........................................................................41
How to Enter the Setup Menus ..................................... 41
How to Edit a Menu...................................................... 41
CAS Menus......................................................................... 42
Setup Global Parameters Menu .......................................... 43
Load a Job..................................................................... 43
Save Setup to Job.......................................................... 44
Job Select Inputs ........................................................... 44
Job Select Input Polarity ............................................... 45
Startup Alarm Delay ..................................................... 45
Keyboard Lock Status................................................... 46
Scanner Address ........................................................... 46
Communications Error Checking ................................. 46
Communications Baud Rate ......................................... 47
Allen-Bradley Protocol ................................................. 47
AC Line Frequency....................................................... 47
Digital Output Polarity.................................................. 48
External Alarm Acknowledge Input ............................. 48
EPROM Information..................................................... 48
Setup Channel Inputs .......................................................... 49
Input Type..................................................................... 49
Pulse Sample Time ....................................................... 50
Channel Name............................................................... 50
Input Units .................................................................... 51
Input Reading Offset..................................................... 51
Linear Scaling Menus ................................................... 52
ii CAS User’s Guide
Contents
Display Format ............................................................. 54
High Process Value....................................................... 54
Input Scaling High Reading.......................................... 55
Input Scaling Low Process Value................................. 55
Input Scaling Low Reading .......................................... 56
Input Filter .................................................................... 56
Setup Channel Alarms ........................................................ 57
High Process Alarm Setpoint........................................ 59
High Process Alarm Type............................................. 59
High Process Alarm Output Number............................ 60
Deviation Alarm Value................................................. 60
High Deviation Alarm Type ......................................... 60
High Deviation Alarm Output Number ........................ 61
Low Deviation Alarm Type.......................................... 61
Low Deviation Alarm Output Number......................... 62
Low Process Alarm Setpoint ....................................... 62
Low Process Alarm Type ............................................. 62
Low Process Alarm Output Number ............................ 63
Alarm Deadband ........................................................... 63
Alarm Delay.................................................................. 64
Manual I/O Test .................................................................. 65
Digital Input Testing..................................................... 65
Digital Output Selection ............................................... 65
Digital Output Test ....................................................... 66
Keypad Test .................................................................. 66
Troubleshooting..........................................................67
Manual System Reset.................................................... 68
Returning the Unit ........................................................ 68
Troubleshooting Stand-Alone Systems .............................. 69
Checking an Analog Input ............................................ 69
Checking Digital I/O..................................................... 69
Checking Computer Supervised Systems ........................... 71
Computer Problems ...................................................... 71
Software Problems........................................................ 72
Changing the EPROM .................................................. 73
Appendix: Linear Scaling Examples .........................75
Example 1 ........................................................................... 75
Example 2 ........................................................................... 76
Example 3 ........................................................................... 77
Glossary ......................................................................79
CAS User’s Guide iii
Contents
iv CAS User’s Guide
Overview
This manual describes how to install, setup, and operate a CAS.
Included are six chapters and a glossary of terms. Each chapter covers a
different aspect of your control system and may apply to different users.
The following describes the chapters and their purpose.
•
Introduction: Gives a general description of the CAS and its
related specifications.
•
Installation: Describes how to install the CAS and its peripheral
devices.
•
Using the CAS: Provides an overview of operator displays used for
system monitoring.
•
Setup: Describes all the setup displays for the device, and how to
access them.
•
Troubleshooting: Gives some basic guidelines for solving opera-
tional problems.
•
Linear Scaling Examples: Provides three examples where linear
scaling is used.
CAS User’s Guide v
System Diagram
The illustration below shows how the parts of the CAS are connected.
When unpacking your system, use the diagram and parts list below to
ensure all parts have been shipped. Please don't hesitate to call Watlow
Anafaze's Technical Service Department if you have problems with
your shipment, or if any CAS components are missing or damaged.
Parts List
•
CAS Scanner
•
Mounting Kit
•
TB-50 Terminal Block
•
50-Pin Ribbon Cable
•
AC Adapter (110V or 220V)
vi CAS User’s Guide
Safety
Watlow Anafaze has made efforts to ensure the reliability and safety of
the CAS and to recommend safe uses in systems applications. Note that
in any application failures can occur.
Good engineering practices, electrical codes, and insurance regulations
require that you use independent external safety devices to prevent
potentially dangerous or unsafe conditions. Assume that the CAS can
fail or that other unexpected conditions can occur.
Install high or low temperature protection in systems where an
overtemperature or undertemperature fault condition could present a fire
hazard or other hazard. Failure to install temperature control protection
where a potential hazard exists could result in damage to equipment and
property, and injury to personnel.
For additional process safety, program a computer or other host device
to automatically reload your desired operating parameters after a power
failure. However, this safety feature does not eliminate the need for
other external, independent safety devices in dangerous conditions.
WARNING
The CAS should never be used as a safety shutdown device. It
should only be used with other approved independent safety
shutdown devices.
Watlow Anafaze also offers ANASCAN®, an optional software
program for IBM-compatible computers. In the event of a controller
reset, ANASCAN will reload the CAS with the current values in
computer memory. The user must ensure that this reset will be safe for
the process. Again, use of ANASCAN does not eliminate the need for
appropriate external, independent safety devices.
Contact Watlow Anafaze immediately if you have any questions about
system safety or system operation.
CAS User’s Guide vii
viii CAS User’s Guide
Introduction
The CAS is a modular monitoring system with 16 fully independent
inputs. It can function as a stand-alone system; the CAS 1/8 DIN front
panel has a Liquid Crystal Display (LCD) and touch keypad for local
display and local parameter entry. You can also use it as the key element
in a computer supervised data acquisition system; the CAS can be
locally or remotely controlled via an RS-232 or RS-485 serial
communications interface.
Features include:
Direct Connection of Mixed Thermocouple Sensors: Directly
connect most thermocouples with the CAS versatile hardware.
Thermocouple inputs feature reference junction compensation,
linearization, PV offset calibration to correct for sensor inaccuracies, T/
C upscale break detection, and a choice of Fahrenheit or Celsius display.
Introduction
Automatic Scaling for Linear Analog Inputs: The CAS
automatically scales linear inputs used with other industrial process
sensors. Simply enter two measurement points. For example, to scale a
PSI sensor enter the endpoints: Low PV is 10 PSI, while High PV is 100
PSI. All other values for that channel will automatically be in PSI.
Flexible Alarm Outputs: Independently set high/low process alarms
and a high/low deviation band alarm for each channel. Alarms can
activate a digital output by themselves, or they can be grouped with
other alarms to activate an output.
Alarm Outputs: You can set high/low deviation and high/low process
alarm setpoints to operate digital outputs as latched or unlatched
functions.
Global Alarm Output: When any alarm is triggered, the Global Alarm
Output is also triggered, and it stays on until you acknowledge it.
Watchdog Timer: The CAS watchdog timer output notifies you of
system failure. Use it to hold a relay closed while the system is running,
so it notifies you of microprocessor failure.
CAS User’s Guide 1
Introduction
Front Panel or Computer Operation: Set up and run the CAS from
the front panel or from a local or remote computer. Watlow Anafaze
offers ANASCAN, our IBM AT or IBM-PC compatible software you
can use to operate the CAS. ANASCAN has these features:
•
Process Overviews
•
Parameter Setup
•
Graphic Trend Plotting
•
Data Logging
Multiple Job Storage: Store up to 8 jobs in protected memory, and
access them locally by entering a single job number or remotely via
digital inputs. Each job is a set of alarm conditions.
Pulse Counter Input Standard: Use the pulse counter input for precise
monitoring of motor or belt speed.
2 CAS User’s Guide
Specifications
Analog Inputs
Introduction
This section contains specifications for inputs, serial interface, system
power requirements, environmental specifications, and physical
dimensions.
Number of Analog Inputs: 16 single-ended/ common ground, plus one
pulse input.
Input Switching: solid state MUX switching.
Input Sampling Rate: 1.5x/second (667 ms) at 60 Hz; 1.25x/second
(300 ms) at 50 Hz.
Analog Over Voltage Protection: ±20 V referenced to digital ground.
A/D Converter: Integrates voltage to frequency.
Input Range: -10 to +60 mV. Other ranges are available with scaling
resistors.
Resolution: 0.006%, greater than 14 bits. (This is the internal
measurement resolution, not the display resolution.)
Calibration: Automatic zero and full scale.
Thermocouple Ranges and Accuracy
T/C Type Range in ºFRange in ºC *Accuracy:
25ºC
Ambient
ºC ºF ºC ºF
J T/C -350 to 1400 -212 to 750 ±0.5 ±0.9 ±1.1 ±2.0
K T/C -450 to 2500 -268 to 1371 ±0.6 ±1.2 ±1.35 ±2.7
T T/C -450 to 750 -268 to 399 ±1.3 ±2.4 ±2.9 ±5.4
S T/C 0 to 3200 -18 to 1760 ±2.5 ±4.5 ±5.6 ±10.1
R T/C 0 to 3210 -18 to 1766 ±2.5 ±4.5 ±5.6 ±10.1
B T/C 150 to 3200 +66 to 1760 ±6.6 ±12.0 ±14.9 ±27.0
N T/C -450 to 2370 -268 to 1299 ±1.0 ±1.8 ±2.25 ±4.1
PL-II T/C +50 to 2012 +10 to 1100 ±0.6 ±1.0 ±1.2 ±2.2
* True for 10% to 100% of span.
*Accuracy:
0 - 50º C Full
Temp. Rang e
T/C Break Detection: Pulse type for upscale break detection.
Milliamp inputs: 0-20 mA (3 ohms resistance) or 0-10 mA (6 ohms
resistance), with scaling resistors.
CAS User’s Guide 3
Introduction
Voltage inputs: 0-12V, 0-10V, 0-5V, 0-1V, 0-500mV, 0-100 mV with
scaling resistors.
Range Input Resistance
0-12 V 85K ohms
0-10 V 50 K ohms
0-5 V 40 K ohms
0-1 V 7.4 K ohms
0-500mV 6.2 K ohms
0-100 mV 1.2 K ohms
0-20 mA 3 ohms
0-10 mA 6 ohms
Source Impedance: for 0-60 mV, measurements are within
specification with up to 500 ohms source resistance.
Digital Inputs
Digital Outputs
Number: 8
Configuration: 8 selectable for remote job selection. Digital input #8 is
only used for external alarm acknowledge.
Input Voltage Protection: Diodes to supply and common. The source
must limit current to 10 mA for override conditions.
Voltage Levels: <1.3V=Low; >3.7V=High (TTL).
Maximum Switch Resistance to Pull Input Low: 1 Kohms.
Minimum Switch Off Resistance: 11 Kohms.
Number: 34
Operation: Open collector output; On state sinks to
logic common.
Total ≤ 700 mA.
Function: Selectable as alarm latched/unlatched.
≤
20 mA for 35 outputs, ≤40 mA for a single output,
Ι
System Digital Outputs
4 CAS User’s Guide
Off State Leakage Current: <.01 mA to DC common.
System Digital Outputs: 1 Global Alarm, 1 CPU watchdog.
Operation: Open collector output; On state sinks to logic common.
≤
mA for 35 outputs,
Ι
Total ≤ 700 mA.
40 mA for a single output,
≤
20
Miscellaneous Specifications
Serial Interface
Type: RS-232 3 wire or RS-485 4 wire.
Isolation:
RS-232 None
RS-485 To EIA RS-485 Specification.
Baud Rate: 2400 or 9600, user selectable.
Error Check: BCC or CRC, user selectable.
Number of Systems: 1 with RS-232 communications;
32 with RS-485 communications.
Introduction
Protocol: Form of ANSI X3.28-1976.
System Power Requirements
Vo lt ag e: 12-24 Vdc
Input Current (no load): 300 mA max
Maximum Current Requirement: 610 mA. (If the reference voltage is
externally loaded, add 1 mA supply current for every 1 mA of load up to
a maximum load of 100 mA. If using the +5V logic supply to power
digital outputs, add 0.6 mA supply current for every 1 mA of load up to
a maximum load of 350 mA. Therefore, the maximum current
requirement is 300 +100 + (0.6 x 350) = 610 mA.)
Environmental Specifications
Storage Temperature: -20 to 60ºC
Operating Temperature: 0 to 40ºC
Humidity: 10 to 95% non-condensing.
Physical Dimensions
CAS: 1.75 lbs., 1.98" x 3.78" x 7.10" (.8 kg, 50 mm x 96 mm x 180
mm.)
TB-50: 3.2" x 3.4" (8.03 cm x 8.53 cm)
CAS User’s Guide 5
Introduction
6 CAS User’s Guide
Installation
Installation
These installation instructions are written for non-technical users; if you
are an electrician or you are technically proficient, they may seem
simple to you.
This section explains installation for the CAS system only. If you are
installing another Watlow Anafaze product, see the manual shipped with
it to learn how to install it. This manual uses these symbols:
DANGER
This symbol warns you about hazards to human life.
WARNING
This symbol warns you of possible damage to property or
equipment.
NOTE
This symbol denotes information you must know in order to
proceed.
CAS User’s Guide 7
Installation
Precautions and Warnings
DANGER
Shut off power to your process before you install the CAS. High
voltage may be present even when power is turned off! Reduce
the danger of electric shock after installation, mount the CAS in
an enclosure that prevents personal contact with electrical com-
ponents.
The CAS measures input signals that are not normally refer-
enced to ground, so the CAS inputs and other signal lines can
have high voltage present even when power is turned off. For
example, if you inadvertently short a thermocouple to the AC
power line.
WARNING
During installation and wiring, place temporary covers over the
housing slots and the rear of the CAS so dirt, pieces of wire, et
cetera don't fall through the slots. Remove these covers after
installation.
Install the CAS so the housing slots receive unrestricted airflow
after installation. Make sure that other equipment does not
block airflow to the slots.
Use #20 or #22 AWG wires and trim wire insulation to ¼" or 5
mm. Wire should fit inside the terminal with no bare wire
exposed, to prevent contact between wires and the grounded
case. Tin any stranded wire.
Support power, input and output wires to reduce strain on the
terminals and to prevent wire removal.
NOTE
Choose a panel location that leaves enough clearance to install and
remove the CAS and its components.
8 CAS User’s Guide
Recommended Tools
Panel Hole Cutters
Other Tools
Installation
Use these tools to install the CAS:
Use any of the following tools to cut a hole of the appropriate size in the
panel.
•
Jigsaw and metal file-for stainless steel and heavyweight panel
doors.
•
Greenlee 1/8 DIN rectangular punch (Greenlee part # 600-68), for
most panel materials and thicknesses.
•
Nibbler and metal file-for aluminum and other lightweight panel
doors.
Use these tools to wire the CAS after you have installed it.
•
Phillips head screwdriver.
•
Flathead screwdriver for wiring.
•
Multimeter.
CAS User’s Guide 9
Installation
CAS Mounting Procedure
Mounting Environment
NOTE
Mount the monitor before you mount the TB-50 or do any wiring.
The monitor's placement affects placement and wiring for other
components in your system.
Install the CAS in a location free from excessive (>40 ºC) heat, dust,
and unauthorized handling. The monitor can mount in any panel
material up to 0.2" thick. (Make sure there is enough clearance for
mounting brackets and terminal blocks; the monitor extends 6.2" behind
the panel face and the screw brackets extend 0.5" above and below it.)
Steps:
1. Cut a hole 3.630±0.020" long by 1.800±0.020" tall in the panel.
This figure shows the mounting hole. Cut carefully; the 0.020" (0.5
mm) tolerances don't allow much room for error. Use a punch, nibbler, or jigsaw, and file the edges of the hole.
Screw Bracket
Screw Bracket
3.630
0.500
± 0.020
0.375
1.800 ± 0.020
0.375
2. Insert the CAS into the hole through the front of the panel.
3. Screw the top and bottom clips in place: insert the screw's lip into
the cutout in the metal housing just behind the front panel. Tighten
the screw.
4. If you expect much panel vibration, use a rear support for the CAS
and its interconnecting cables.
10 CAS User’s Guide
TB-50 Mounting Instructions
To connect alarms to the CAS System, wire them to the TB-50 (50-pin
terminal block). These steps tell you how to mount it on any flat surface.
(Please follow this procedure exactly, so you do not damage the
terminal block, ribbon cable, or monitor.)
1. Choose a mounting location. Be sure there is enough clearance to
install and remove the TB-50; it measures 3.4" long x 3.2" wide x
1.27" tall.
2. Watlow Anafaze shipped the TB-50 to you in an antistatic bag.
Make sure these parts are also in the bag:
• Five plastic standoffs.
• Five 6-32 screws.
• Five cable tie wraps.
• One 50-pin ribbon cable.
• Five ribbon cable clamps.
3. Snap four of the plastic standoffs into the four mounting holes on
the TB-50.
There are also four smaller holes on the terminal board, as shown here.
These holes are for the cable tie wraps
them. You'll use these holes to secure wiring to the terminal block. (See
Wiring Outputs in this chapter for help installing cable tie wraps.)
Installation
—
the plastic standoffs won't fit
B
A
B
B
A
B
Holes labeled "A" are mounting holes.
Holes labeled "B" are tie wrap holes.
3938B
3738A
4140
42
36
35
33
34
A
4443
32
29
3031
504948474645
262728
25242322212019181716151413B
12345678910111213A
A
CAS User’s Guide 11
Installation
1. Place the TB-50 where you will mount it and use a pencil to trace
around the standoffs.
2. Drill and tap #6-32 holes in the locations you marked.
3. Place the TB-50 where you will mount it. Insert the #6 screws in the
standoffs and tighten them.
NOTE
Save the cable tie wraps, ribbon cable, and ribbon cable clamps.
You'll use them when you wire outputs to the TB-50 and when you
connect the ribbon cable.
WARNING
Do not connect power to the CAS now. Test the unit first, as
explained in the Power Wiring and System Test section.
12 CAS User’s Guide
General Wiring Recommendations
Use the cables below or their equivalent. For best results, use
appropriate materials, proper installation techniques and the correct
equipment. For example, choose wire type by function, installation
requirements, and the likelihood of mechanical or electrical problems at
your installation.
Installation
Function MFR P/N
Analog inputs Belden #9154
Belden #8451
Thermocouple inputs Thermocouple
extension wire
Digital I/O Belden #9539
Belden #9542
Ribbon Cable
Computer
Communication:
RS-232 or RS-485
Belden #9729
Belden #9730
Belden #9842
Belden #9843
No. of
Wires
2
2
220
9
20
50
4
6
4
6
WARNING
Never wire bundles of low power Watlow Anafaze circuits next
to bundles of high power AC wiring. Always physically separate high power circuits from the monitor. If possible, install
high voltage AC power circuits in a separate panel.
AWG
20
22
24
24
24
24
24
24
•
Use stranded wire. (Use solid wire for fixed service only).
•
Use #18 or #20 AWG wire. Larger or smaller sizes may be difficult
to install, may break easily, or may cause intermittent connections.
•
Use shielded wire. (The electrical shield helps protect the CAS from
electrical noise.) Connect one end of the input wiring shield to the
CAS panel's 120 Vac panel ground, and connect one end of the output wiring shield to the CAS panel's 120 Vac panel ground. If these
instructions do not apply to your system, contact Watlow Anafaze
for more information.
For additional noise suppression measures, see Noise Suppression.
CAS User’s Guide 13
Installation
Grounding
Connect the CAS power supply common to an external ground at only
one point, to avoid ground loops that can cause instrument errors or
malfunctions. Since the CAS uses a non-isolated measurement system,
it has the following connections to power supply common:
•
Analog Common TB1 pins 5, 6, 11, & 12.
•
Reference Common, TB1 pin 17.
•
Communications ground (TB1 pins 23 & 24) if using RS-232.
•
Power Supply Ground, TB2 pin 2.
Watlow Anafaze strongly recommends that you:
•
Do not connect to earth ground unless recommended by the factory
for a specific application.
•
Isolate outputs through solid state relays, where possible.
•
Isolate digital inputs from ground through solid state relays. If you
can't do that, then make sure the digital input is the only place that
one of the above pins connects to ground.
•
If you are using RS-232 from an un-isolated host, don't connect any
other power common point to earth ground.
Thermocouple Wiring
Input Wiring
Use 18 or 20 AWG thermocouple (T/C) extension wire for all
T/C inputs.
NOTE
Most thermocouple wire is solid unshielded wire. Use shielded wire
if required at your installation; ground one end only.
Since the CAS has single ended inputs, it has little protection from
common mode voltage sources. Therefore, Watlow Anafaze highly
recommends that you use ungrounded thermocouples with the external
thermocouple sheath electrically connected to earth ground.
You can use 400 to 500 feet of thermocouple extension wire, depending
on wire type and size, and keep to accuracy and source impedance
specifications. Always install T/C wiring in a separate conduit away
from AC power (the 120 VAC control supply) and high power (240
VAC or higher) wiring.
Use multicolor stranded shielded cable for analog inputs. We
recommend that you use #20 AWG wire. (If the sensor manufacturer
requires it, you can also use #22 or #24 AWG wiring.) Most inputs use a
shielded twisted pair; some require a 3 wire input.
14 CAS User’s Guide
Communications Wiring
Installation
Large systems can pull an extra pair of wires to the computer
communications wiring. The extra pair services a sound power phone
system for communications between the CAS and a computer. If you
choose this option for maintenance, calibration checking, Watlow
Anafaze recommends a David Clark #H5030 system.
CAS User’s Guide 15
Installation
Wiring: Noise Suppression
Symptoms of RFI
Avoiding Noise Problems
If the outputs control dry contact electromechanical relays with
,
inductive loads
Interference (RFI, or "noise"). This section explains how to avoid noise
problems; read it before you wire the CAS.
•
If your system displays the following symptoms, suspect RFI.
•
The CAS display blanks out and then reenergizes as if power had
been turned off for a moment.
•
The process value does not display correctly.
RFI may also damage the digital output circuit, so digital outputs will
not energize. If the digital output circuit is damaged, return the system
to Watlow Anafaze for repair.
like alarm horns, you may get Radio-Frequency
Use these techniques to avoid noise problems.
Where possible, use solid state relays (SSRs) instead of
electromechanical (EM) relays. If you must use EM relays, try to avoid
mounting them in the same panel as Watlow Anafaze equipment.
Separate the 120 Vac power leads from the low level input and output
leads connected to the CAS. Don't run the digital output or PID control
output leads in bundles with 120 Vac wires. (Never run input leads in
bundles with high power leads
If you must use EM relays and you must place them in a panel with
Watlow Anafaze equipment, use a .01 mF capacitor rated at 1000 Vac
(or higher) in series with a 47 ohm, ½ watt resistor across the normally
open (NO) contacts of the relay load. This network is known as an arc
suppressor or snubber network.
You can use other voltage suppression devices, but they are not usually
required. For instance, you can place a metal oxide varistor (MOV)
rated at 130 Vac for 120 Vac control circuits across the load, which
limits the peak AC voltage to about 180 Vac. You can also place a
transorb (back to back zener diodes) across the digital output, which
limits the digital output loop to 5 Vdc. (These parts are available from
Watlow Anafaze.)
—
see the General Wiring section.)
16 CAS User’s Guide
These steps will eliminate most noise problems. If you have further
problems or questions, please contact Watlow Anafaze.
General Wiring
This section explains how to test your installation before you connect
power to it and how to connect inputs and outputs to it.
Power Wiring and System Test
When you have installed the system and the TB-50, use this checklist to
connect them. (These instructions are written so that non-electricians
can understand them. If you are an experienced electrician, they may
seem elementary to you. If so, feel free to skim them.)
Connecting Power and TB-50 to CAS
1. Remove the temporary covers on the CAS housing.
2. Connect the power supply. Do not turn on the AC power yet.
3. Connect the ribbon cable to the system, as shown here. Plug it in so
the red stripe is on the left side as you face the back of the system.
Installation
TB1-1+
TB2 -2
Red
Stripe
4. Connect the ribbon cable to the TB-50. The cable is keyed, so you
cannot insert it backwards.
-
CAS User’s Guide 17
Installation
WARNING
Do not turn on AC power yet. First test the connections, as
explained in the Connections Test section (below).
Excessive voltage to the CAS will damage it, and you will need
to return it to Watlow Anafaze for repair. If you are not using
the Watlow Anafaze power supply, read the next section completely and follow its instructions before you apply power.
Connections Test
1. Unscrew the four screws on the sides of the front panel.
2. Gently slide the electronics assembly out of the case.
You have now removed the parts of the CAS which will be damaged by excess voltage, so plug in the transformer power supply
and use a voltmeter to check voltages:
3. Touch the meter Common lead to Back Terminal Block 2 (TB2) terminal 2 on the CAS. The voltage on TB2 terminal 1 should then be
+12 to 24 Vdc (no load).
4. If the voltages are within the limits described above,
A. Turn off power.
B. Slide the electronics assembly back into the processor module's
casing.
C. Reinsert screws into the screw holes on the casing and tighten
them.
D. Turn the power back on. The display should light up, and after
about a second the single channel display should appear.
5. If you have not connected analog inputs yet, the CAS may display a
"T/C Break" alarm message for each channel. This is normal; to
clear the alarm messages, press ALARM ACK once for each alarm
message.
18 CAS User’s Guide
Outputs
Wiring Outputs
Installation
NOTE
All digital outputs are sink outputs referenced to the 5Vdc supply.
These outputs are low (pulled to common) when they are ON.
All digital inputs are Transistor-Transistor Logic (TTL) level inputs
referenced to control common.
The alarm outputs are located on the 50-pin header which connects to
the 50-pin flat ribbon cable. This section explains how to wire and
configure alarm outputs.
The digital outputs sink current from a load connected to the CAS'
internal power supply, or from an external power supply referenced to
CAS ground.
•
If you use an external power supply, do not exceed +12 volts.
•
If you tie the external load to ground, or if you cannot connect it as
shown below, then use a solid state relay.
•
If you connect an external supply to earth or equipment ground, use
solid state relays to avoid ground currents. (Ground currents may
degrade analog measurements in the CAS).
The outputs conduct current when they are "True". The maximum
current sink capability is 20 mA (for all outputs, refer to spec. for
details). They cannot "source" current to a ground load.
CAS User’s Guide 19
Installation
Using the Cable Tie Wraps
When you have wired outputs to the TB-50, use the cable tie wraps
shipped with it. This diagram shows the cable tie wrap holes.
A
B
A
3938B
4140
42
4443
504948474645
36
B
B
A
B
Holes labeled "A" are mounting holes.
Holes labeled "B" are tie wrap holes.
3738A
35
33
34
32
29
3031
262728
25242322212019181716151413B
12345678910111213A
A
Each row of terminals has a cable tie wrap hole at one end. Thread the
cable tie wrap through the cable tie wrap hole. Then wrap the cable tie
wrap around the wires attached to that terminal block.
20 CAS User’s Guide
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