Control Technologies CTI 2552-A Operating instructions

CTI 2552-A
8-CHANNEL ISOLATED RTD INPUT MODULE
INSTALLATION AND OPERATION GUIDE
Ver. 1.2
CTI Part # 062-00306-012
062-00303-011
2552-AIOG 020106 $25

ii CTI 2552-A Installation and Operation Guide
Copyright © 2006 Control Technology Inc.
All rights reserved.
This manual is published by Control Technology Inc., 5734 Middlebrook Pike, Knoxville, TN 37921.
This manual contains references to brand and product names which are tradenames, trademarks,
and/or registered trademarks of Control Technology Inc. Siemens® and SIMATIC® are registered
trademarks of Siemens AG. Other references to brand and product names are tradenames,
trademarks, and/or registered trademarks of their respective holders.
DOCUMENT DISCLAIMER STATEMENT
Every effort has been made to ensure the accuracy of this document; however, errors do occasionally
occur. CTI provides this document on an "as is" basis and assumes no responsibility for direct or
consequential damages resulting from the use of this document. This document is provided without
express or implied warranty of any kind, including but not limited to the warranties of
merchantability or fitness for a particular purpose. This document and the products it references are
subject to change without notice. If you have a comment or discover an error, please call us toll-free
at 1-800-537-8398.

CTI 2552-A Installation and Operation Guide iii
PREFACE
This Installation and Operation Guide provides installation and operation instructions for the CTI
2552-A Eight Channel Isolated RTD Input Module for SIMATIC® 505 programmable controllers.
We assume you are familiar with the operation of SIMATIC® 505 series programmable controllers.
Refer to the appropriate SIMATIC® user documentation for specific information on the SIMATIC®
505 programmable controllers and I/O modules.
This Installation and Operation Guide is organized as follows:
Chapter 1 provides a description of the module.
Chapter 2 covers installation and wiring.
Chapter 3 is a guide to troubleshooting.

iv CTI 2552-A Installation and Operation Guide

CTI 2552-A Installation and Operation Guide v
TABLE OF CONTENTS
PREFACE ......................................................................iii
TABLEOFFIGURES ........................................................... vii
USAGE CONVENTIONS ........................................................ ix
CHAPTER 1. DESCRIPTION ..................................................... 1
1.1 Asynchronous Operation ................................................ 1
1.1.1 Compatibility with Immediate I/O ................................ 1
1.2 100 Ohm or 120 Ohm RTDs ............................................. 1
1.3DigitalWordMap ..................................................... 2
1.4 RTD Input to Digital Conversion .......................................... 2
1.5 Effect of Out-of-Range Input Signals ....................................... 3
1.6Resolution............................................................ 4
CHAPTER 2. INSTALLATION ................................................... 5
2.1PlanningtheInstallation................................................. 5
2.2 Calculating the I/O Base Power Budget ..................................... 5
2.3 Unpacking the Module .................................................. 5
2.4 Configuring the Module ................................................. 6
2.4.1 Select Temperature or Millivolt Input .............................. 6
2.4.2Selecting3Wireor4WireOperation .............................. 6
2.4.3 Selecting 100 Ohm or 120 Ohm RTD Inputs ........................ 6
2.4.4 Selecting Digital Filtering ....................................... 7
2.4.5 Select Degrees Celsius or Fahrenheit .............................. 7
2.5 Inserting the Module Into the I/O Base ..................................... 8
2.6 Wiring the Input Connectors ............................................. 9
2.7 Checking Module Operation ............................................. 13
CHAPTER 3. TROUBLESHOOTING .............................................. 15
SPECIFICATIONS .............................................................. 17
JUMPER SETTINGS LOG SHEET ................................................. 19
LIMITED PRODUCT WARRANTY ............................................... 21
REPAIRPOLICY ............................................................... 23

vi CTI 2552-A Installation and Operation Guide

CTI 2552-A Installation and Operation Guide vii
TABLE OF FIGURES
Figure 1 The 2552-A 8-Channel RTD Input Module .....................................iii
Figure 2 Word Input to the PLC from the Module ...................................... 2
Figure 3 Example Change Input Level ............................................... 2
Figure 4 Effect of Voltage Input - 100 Ohm Platinum ................................... 3
Figure 5 Effect of Voltage Input - Millivolts ........................................... 3
Figure 6 Input Resolution ......................................................... 4
Figure 7 Factory Configuration Jumper Settings ....................................... 7
Figure 8 Configuration Jumper Locations ............................................ 8
Figure 9 Copper Wire Table at 25 Degrees Celsius ..................................... 9
Figure 10 Screw Terminal Block Wiring ............................................. 10
Figure 11 Wiring Diagram for 2, 3, or 4 Wire RTD ..................................... 11
Figure 12 Wiring Diagram for Millivolt Measurements .................................. 12
Figure 13 Example I/O Configuration Chart .......................................... 13
Figure 14 Troubleshooting Matrix .................................................. 15
Figure 15 Factory Configuration Jumper Settings ...................................... 19

viii CTI 2552-A Installation and Operation Guide

CTI 2552-A Installation and Operation Guide ix
NOTE:
Notes alert the user to special features or procedures.
CAUTION:
Cautions alert the user to procedures which could damage equipment.
WARNING:
Warnings alert the user to procedures which could damage equipment and endanger the user.
USAGE CONVENTIONS

xCTI 2552-A Installation and Operation Guide

CTI 2552-A Installation and Operation Guide 1
CHAPTER 1. DESCRIPTION
The 2552-A Eight Channel RTD Input Module is a member of Control Technology's family of I/O
modules compatible with the SIMATIC® 505 series programmable controllers. The Model 2552-A
is designed to translate 100 Ohm platinum RTDs, 120 Ohm nickel RTDs or millivolt input signals
into equivalent digital words which are then sent to the programmable controller (PLC).
The 2552-A RTD Input Module features built-in independent two, three, or four lead compensation
for each RTD input. Support for other RTD types is available through special request from the
factory. Call CTI at 1-800-537-8398 to determine if support is available for your special RTD type.
1.1 Asynchronous Operation
The module operates asynchronously with respect to the PLC; a scan of the PLC and input sampling
of the module do not occur at the same time. Instead, the module will translate all inputs in one
module update (15 milliseconds maximum) and store the translated words in a buffer memory. The
PLC retrieves the stored words from the module buffer memory at the start of the I/O scan.
1.1.1 Compatibility with Immediate I/O
The Model 2552-A has been tested and is compatible with the Immediate read function of the
SIMATIC® 545 and 555 PLC.
1.2 100 Ohm or 120 Ohm RTDs
Each of the module's eight channels may be configured to receive either a 100 Ohm platinum RTD or
a 120 Ohm nickel RTD input signal (two, three or four wire) or a DC voltage signal ranging from 0 to
100 millivolts. Selection of 100 Ohm or 120 Ohm RTDs or millivolts are made via internal switch
and jumper settings (see sections 2.4.1 and 2.4.5).

2CTI 2552-A Installation and Operation Guide
Figure 2 Word Input to the PLC from the Module
Figure 3 Example Change Input Level
1.3 Digital Word Map
RTD and/or millivolt signals are translated into a 14-bit digital word. Since the PLC requires a 16-bit
input word, the 14-bit value from the converter is placed into a 16-bit word for transmittal to the PLC.
As shown in the following figure, of the two bits not used for the digital word, one is used to show
the sign of the word, while the other is used to note values which are "overrange."
1.4 RTD Input to Digital Conversion
The following equations may be used to calculate the digital word in decimal format which will result
from a particular RTD input:
RTD Mode, Digital Word (WX) = Degrees X 10
Millivolt Mode, Digital Word (WX) = Millivolts X 100
As an example, the following figure illustrates the effects of a change in input level going from 0
degrees to 102.4 degrees in the RTD Input Mode.

CTI 2552-A Installation and Operation Guide 3
Figure 4 Effect of Voltage Input - 100 Ohm Platinum
Figure 5 Effect of Voltage Input - Millivolts
1.5 Effect of Out-of-Range Input Signals
RTD inputs exceeding 849.8 degrees C for 100 Ohm platinum or 260.0 degrees C for 120 Ohm nickel
will cause the overrange bit to be set. A maximum temperature of 849.9 degrees C for 100 Ohm
platinum or 260.1 degrees C for 120 Ohm nickel will be returned for any positive overrange input.
Similarly an input below -199.8 degrees C for 100 Ohm platinum or -79.8 degrees C for 120 Ohm
nickel will cause the overrange bit to be set. A minimum temperature of -199.9 degrees C for 100
Ohm platinum or -79.9 degrees C for 120 Ohm nickel will be returned for any negative underrange
input.
Millivolt inputs exceeding 103.04 millivolts will cause the overrange bit to be set. A reading of
103.05 millivolts will be returned for any positive overrange input.
Similarly a millivolt input below 0 millivolts will cause the overrange bit to be set. A reading of 1
millivolt will be returned for any negative underrange input.

4CTI 2552-A Installation and Operation Guide
Figure 6 Input Resolution
1.6 Resolution
The module has a resolution of approximately 0.2 degrees C, 0.4 degrees F or exactly 0.02 millivolts.
The chart below shows the corresponding input resolution per step for each of the input configuration
modes:

CTI 2552-A Installation and Operation Guide 5
CAUTION:
HANDLING STATIC SENSITIVE DEVICES
The components on the 2552-A module printed circuit card can be damaged by static electricity
discharge. To prevent this damage, the module is shipped in a special anti-static bag. Take the
following precautions before removing the module from the bag, when opening the module, and
when handling the printed circuit card during configuration.
Discharge any static potential by holding the module in its anti-static bag and touch the metal
chassis of the PLC. During the configuration step, hold the printed circuit card only by its
edges. Do not touch the circuit card pin connectors, or solder connections.
CHAPTER 2. INSTALLATION
The installation of the 2552-A Eight Channel RTD Input Module involves the following steps:
1. Planning the installation
2. Configuring the module
3. Inserting the module into the I/O base
4. Wiring the module input connector
5. Checking module operation
The steps listed above are explained in detail in the following pages.
2.1 Planning the Installation
Planning is the first step in the installation of the module. This involves calculating the I/O base
power budget and routing the input signal wiring to minimize noise. The following sections discuss
these important considerations.
2.2 Calculating the I/O Base Power Budget
The Model 2552-A requires 2.8 watts of +5 V power from the I/O base. Use this figure to verify that
the base power supply capacity is not exceeded.
2.3 Unpacking the Module
Open the shipping carton and remove the special anti-static bag which contains the module.
After discharging any static build-up, remove the module from the static bag. Do not discard the

6CTI 2552-A Installation and Operation Guide
NOTE: FACTORY SHIPPING CONFIGURATION
As shipped, all input channels are configured 100 Ohm platinum, 3 wire RTDs, degrees Celsius
and digital filtering enabled for temperature measurements.
static bag. You will need it for the following configuration procedure.
2.4 Configuring the Module
The Model 2552-A must be configured for 100 Ohm platinum or 120 Ohm nickel RTDs (2, 3 or 4
wire) or millivolt range and digital filtering/no filtering mode before wiring the input connectors and
inserting the module into the I/O base.
Changing the module input channel configuration involves the following steps:
1. Selecting temperature or millivolt measurement
2. Selecting 3 or 4 wire compensation
3. Selecting 100 Ohm platinum or 120 Ohm nickel RTD input mode for each channel
4. Selecting digital filtering or no filtering for the module
5. Logging the configuration jumper settings for future reference
Each of these steps is described in the following sections.
2.4.1 Select Temperature or Millivolt Input
Locate DIP switch SW2 (Temperature/Millivolt Switches in Figure 8) on the 2552-A card and for
each input 1-8 select either Temperature or Millivolt by turning each switch open or closed. The
"CLOSED" position corresponds to Temperature.
2.4.2 Selecting 3 Wire or 4 Wire Operation
Locate the 8 "3 wire/4 wire" jumpers corresponding to input channels 1 through 8. These jumpers are
located adjacent to the input terminal strip (see Figure 8). For each input channel, select 3 wire mode
by placing the jumper in the "3 wire" position or 4 wire mode by placing the jumper in the "4 wire"
position. If 2 wire operation is desired, use the "4 wire" position.
2.4.3 Selecting 100 Ohm or 120 Ohm RTD Inputs
Locate DIP switch SW1 (RTD Type Switches in Figure 8) on the 2552-A circuit card and select
either 100 or 120 type RTD for each of the eight inputs by turning each switch open or closed. The
"CLOSED" position corresponds to 100 Ohm platinum RTD input.

CTI 2552-A Installation and Operation Guide 7
WARNING:
Remove power from the I/O base before inserting or removing a module.
2.4.4 Selecting Digital Filtering
Locate the Digital Filtering Jumper JP3 (see Figures 8). To enable digital filtering, set the jumper in
the ENABLED position. Since many analog input signals contain noise, CTI recommends using
digital filtering unless maximum response time is required.
2.4.5 Select Degrees Celsius or Fahrenheit
Locate the temperature scaling jumper JP4 on the right hand side of the module (see Figure 8) and
select either degrees Fahrenheit or Celsius by positioning the jumper in the DEG F or DEG C
position.
2.5 Inserting the Module Into the I/O Base
Insert the module into the I/O base by carefully pushing the module into the slot. When the module is
fully seated in the slot, tighten the captive screws at the top and bottom to hold the module in place.
To remove the module from the I/O base, loosen the captive screws, then remove the module from the
I/O base. Be careful not to damage the connector card at the back of the module when inserting or
removing the module.
Figure 8 Jumper Locations

8CTI 2552-A Installation and Operation Guide
Copper Wire Table at 25 Degrees Celsius
2.6 Wiring the Input Connectors
RTD input signals are accepted through a screw terminal connector block located on the front of the
module. Consult the RTD manufacturer's recommendations for selecting the input wire type and size.
The Model 2552-A uses a fixed connector to terminate field wiring. This is used because the
chemistry of a removable connector may have an adverse effect on the accuracy of the measurement.
CTI has carefully selected a connector that minimizes this effect.
Refer to Figure 10 for correct wiring for 2, 3, or 4 wire RTDs to the Model 2552-A. Each channel
group consists of four screw terminals. See Figure 10.
The Model 2552-A may compensate for up to 20 Ohm of lead resistance per wire. Use the table
below in planning the maximum distance the RTD may be located from the module.

CTI 2552-A Installation and Operation Guide 9
Figure 9 Screw Terminal Block Wiring
To assign an input to a specific channel, locate the appropriate channel position on the screw terminal
block as shown in the following figure:

10 CTI 2552-A Installation and Operation Guide
CAUTION:
RTD wires must be of the same gauge.
Figure 10 Wiring Diagram for 2, 3, or 4 Wire RTD