Siemens Simatic S5 IP 240 Technical Document

SIEMENS
SIMATIC S5
1P 281
Equipment Manual
m
Table of Contents
I
I
ESD Guidelines
Notes on Safety
Warning
Table of Contents
Introduction
General
Function Description
Hardware Settings
Software Settings
Interrupt Processing
Commissioning
the
Counter Module
Operating Modes
and Functions
Programming Example
Technical Specifications
Release 01
Order No: 6ES5998–0KP21
Definition of Terms
Index
1
2
3
4
5
6
7
8
9
10

SIMATIC is a trade mark of Siemens.
Subject to change without prior notice. Siemens Aktiengesellschaft
Although the contents of this publication have been checked for agreement with the hardware
and software described, we do not accept liability for total agreement since differences cannot
be completely excluded. The information in this publication is checked at regular intervals and
necessary corrections included in the next release. Your suggestions for improving this publica-
tion are welcome.
I
@ Copyright Siemens AG 1992 All Rights Reserved
I
Passing on and reproduction of these documents, and utilization and disclosure of their con-
tents is prohibited unless specifically authorized. Violations shall be cause for damage liability.
All rights reserved, particularly in the event a patent is issued or a utility model patent is regis-
tered.

ESD Guidelines
Guidelines for Handling Electrostatic Sensitive
Devices
(ESD)
1
What Does ESD Mean?
Almost all SIMATIC–TELEPERM modules contain many integrated blocks or elements which use
MOS technology. The technology used makes these electronic components very sensitive to
overvoltages and thus to electrostatic discharge.
The German abbreviation for such modules is
“EGB”: Elektrostatisch (2efahrdeten Elauelemente
EJaugruppen
Next to this abbreviation you will often find the common international abbreviation
“ESD”: Electrostatic Sensitive
!2evice
When found on cabinets, module subracks or packaging, the symbol shown below indicates that
electrostatic sensitive components have been used in this device and the module is thus sensitive
to touch.
A
ESDS can be destroyed by voltages and energies far below those perceived by humans. Such
voltages can even occur when a component or a module is touched by a person who is not statical-
ly discharged. Components which have been subjected to such overvoltages can usually not be
immediately identified as defective since a malfunction may not occur until the module has been in
operation for a longer period of time.
To be perceived by humans, the following minimum voltages are required:
– To be felt – 3500 volts
– To be heard – 4500 volts
– To be seen – 5000 volts
But a fraction of this voltage can already damage or destroy electronic components.
Components which have been damaged, overloaded or weakened by static discharge can mal-
function temporarily when average technical specifications are deviated from. A few examples are
listed below.” -
—
—
—
—
Temperature changes
Impact
Jarring
Changes in stress
Only through rigorous use of protective measures and careful adherence to the handling guide-
lines can malfunctions and downtime of ESD modules be effectively prevented.
@ Siemens AG
E–1

ESD Guidelines
2 When Does a Static Charge Occur?
You can never be absolutely certain that you yourself or the materials and tools you are using are
not electrostatically charged.
Small charges of up to 100 V are common but these can increase to 35,000 V in a very short time!
Examples:
– Walking on carpeting
– Walking on plastic -
flooring
– Sitting on upholstered
chair
– Unsoldering device
made of plastic
– Plastic coffee cups
– Plastic covers
– Books and pads with
synthetic binding
up to 35000 v
up to
12000 v
up to
18000 V
up to
8000 V
up to 5000 v
up to
5000 v
up to 8000 V
3
●
●
4
●
●
●
●
●
9
Important Protective Measures Against Static Charging
Since most plastics have a strong tendency to charge, it is imperative that they be kept away
from sensitive components.
Be sure to provide good grounding of people, your workplace and the packaging when working
with electrostatic sensitive components.
Handling ESD Modules
As a matter of principle, electronic modules should not be touched unless the work to be per-
formed on them makes this absolutely necessary.
Components should not be touched unless
– you are continuously grounded with an ESD bracelet
or
– you are wearing ESD shoes or ESD shoe protective
grounding strips on an ESD floor.
Before touching an electronic module, your own body must be discharged. The easiest way to
do this is to touch a conductive, grounded object (e.g., blank metal parts of switching cabinets,
water pipes, etc.) immediately prior to touching the component.
Modules should not come in contact with chargeable and highly insulating materials (e.g., plas-
tic foil, insulating tabletops, synthetic fiber clothing).
Modules should only be placed on conductive surfaces (e.g., table with
ESD covering, conduc-
tive ESD foam, ESD packaging bag, ESD shipping container).
Do not allow modules in the vicinity of CRTs, monitors or television sets (minimum distance to
the screen >10 cm).
E – II @Siemens AG

ESD Guidelines
Required ESD protective measures are shown in the figure below.
o
f
—
—
5
b
t
a
a Conductive floor
b ESD table
c
ESD shoes
d
ESD shop coat
e
ESD bracelet
f Grounding connection of the
cabinets
Measuring and Modifying ESD Modules
● Measurements may not be performed on the modules unless
– the measuring device is grounded (e.g., with protective conductor)
or
– the measuring head is briefly discharged (e.g., touching blank metal part
of the controller housing) prior to measuring when using a floating mea-
suring device.
● For soldering use only a grounded soldering device.
6Shipping ESD Modules
As a matter of principle, modules and components must always be stored or shipped in conduc-
tive packaging (e.g., metallized plastic boxes, metal cans).
When packaging is not conductive, the modules must be wrapped in conductive material prior to
packaging. For example, conductive foam rubber, ESD bags, household aluminum foil or paper
can be used (never use plastic bags or foil).
Be sure that the conductive packaging of modules with built–in batteries does not touch or short
circuit the battery connections (if necessary, cover the connections with insulating tape or material
beforehand).
@ Siemens AG
E – Ill

Notes on Safetv
Notes on Safety for the User
1 General Information
This manual contains information required for operation of the described products in accordance
with their intended applications. The manual is written for qualified personnel who have received
special training or have adequate knowledge of measuring, and closed and open loop control
technology (subsequently called automation technology).
Safe installation and commissioning, and safe operation and maintenance of the described pro–
ducts are dependent on a knowledge of the safety notes and warnings contained in this manual
and correct observation of same. Only qualified personnel as described in item 2 have the special-
ized technical knowledge required to fully understand the safety notes and warnings as stated in
this manual, to interpret this information correctly in concrete situations, and to put this informa-
tion to use in actual practice.
This manual is a permanent part of the scope of delivery even if a separate order is required for
logistics reasons. Forclarity’s sake, this manual does not contain all details concerning all models
of the described product, and cannot cover every conceivable setup, and type of operation or
maintenance. Contact your local
Siemens office if you desire additional information or if special problems arise which are not co–
vered in sufficient detail by this manual.
In addition, be aware that the contents of this product documentation do not constitute a part of a
previous or existing agreement, promise or a legal relationship, and are not intended to alter same.
All obligations on the part of
Siemens are based on the respective purchase order which also con-
tains the complete and solely valid warranty provisions. The information in this manual neither
wi–
dens nor restricts these contractual warranty regulations.
2
Qualified Personnel
Unqualified work on the device/system or noncompliance with warning notes contained in this
manual and warnings posted on the device/system cabinet can cause severe personal injury or
property damage. For this reason, only sufficiently qualified personnel may perform work on this
device/system.
The following personnel are considered qualified for the purposes of the safety-related notes in
this manual or on the product itself:
. Either programming personnel familiar with the safety concepts of automation technology
● Oroperating personnel who have been instructed in the handling of devices used in automation
technology, and who are aware of the portions of this manual covering operating
● Or maintenance and service personnel who have been trained to make repairs on devices used
in automation technology, and are authorized to commission, ground and label electrical cir-
cuits and devices/systems in accordance with safety standards.
~ Siemens AG s–l

Notes on Safety
3
Notes Concerning Danger
The following warnings are provided for your personal safety and for the prevention of damage to
the described product or connected devices.
Notes on safety and warnings to avoid endangering the life and health of users or maintanence
personnel and to prevent prope~ damage are indicated as shown below. The terms used in this
manual and the notes on the products themselves have the following meaning:
CEEl
Indicates that loss of life, severe per-
sonal injury or substantial property
damage W result if proper precau-
tions are not taken.
Indicates that minor personal injury or
property damage can result if
proper precautions are not taken.
I Attention
I
DiEEl
indicates that loss of life, severe per-
sonal injury or substantial property
damage cm result if proper precau–
tions are not taken.
I-!w_l
Important information concerning
the product, handling of the product
or that part of the manual which re-
quires particular attention.
Corresponds to the above definition
for “note” or “caution” when used in
this manual for information concerning
safetv.
.
s – II
@Siemens AG

Notes on Safetv
4 Operation in Accordance with Intended Use
9
●
The device/system and/or the system components may only be used for the applications con-
tained in the catalog and technical specifications, and only in combination with devices or com-
ponents of other manufacturers which have been recommended and/or approved by
Siemens.
The described rxoduct has been develo~ed, manufactured, tested and documented in com-
pliance with applicable safety standards: Under normal circumstances, the product will not
damage human health or property if the described handling regulations and safety notes con-
cerning programming, installation, operation in accordance with intended use, and mainte-
nance are adhered to.
A
!
Warning
/
.
\
●
●
●
●
When the housing or the protection against accidental contact is removed,
or when the system cabinet is opened, certain parts of these devices/sys-
tems which can contain dangerous voltages become accessible.
Work on this device/system may only be performed by appropriatelyquali-
fied personnel.
This personnel must be thoroughly familiar with all sources of danger and
maintenance measures as specified in this manual.
Correct and safe operation of the product requires proper shipment, stor-
age, setup and installation, and careful operating and maintenance.
5
Notes on Programming and Installing the Product
Since the Droduct is normallv used as a Dart of a larger svstem or plant, these notes are intended as
a guide to safe integration of the product into its e;virofiment. “
The following facts require particular attention.
A
!Note
Even when devices of automation technology are designed to provide maximum
conceptual
safe~ (e.g., multi–channel setup), it is still absolutely essential to ad-
here precisely to the instructions in this manual since safety measures built into
the device/system to prevent dangerous errors can be rendered useless by im-
proper handling; incorrect handling can also create additional danger sources.
@ Siemens AG
s – Ill

Notes on Safetv
Notes on installation and maintenance of the product – based on the application – are listed be-
low.
A
, Warning
a
The safety and accident prevention regulations applicable to the specific appli-
cation must be adhered to.
Built–in devices for housings or cabinets may only be used and operated when
completely installed in the housing or cabinet; desktop or portable models may
only be used and operated when the housing is closed.
A power disconnector switch or a fuse must be provided in the building installa-
tion for facilities with a fixed connection (stationary devices/systems) without
all–pole power disconnector switches and /or fuses. The facility must be con-
nected to a protective conductor.
The grounded protective contact electrical outlet for devices/systems with per-
manently connected, non–removable connection lines and without all–pole
power disconnector switches must be installed near the device and be easily
accessible.
Before commissioning devices operated with power network voltage, check to
determine whether the set nominal voltage range matches the local power
vol–
tage.
When a 24–V supply is used, a reliable electrical separation of extra low vol–
tages must be provided. Use only powerpacks manufactured in accordance
with IEC 364–4–41 or HD 384.04.41 (VDE 0100, part 410).
Fluctuations or variations of the power voltage from the nominal value may not
exceed the tolerance ranges stated in the technical specifications. Otherwise
the occurrence of malfunctions and dangerous states on the electrical module
systems cannot be excluded.
Measures must be provided by which an interrupted program can be properly
restarted aftera drop in voltage or a power loss. This must not cause dangerous
operating situations even for short times. If necessary, “emergency OFF” must
be forced.
“Emeraencv OFF” svstems in accordance with EN 60204 IEC 204 (VDE 01 13)
must r~mai;
effectiv; in all operating modes of the automation syste’m. Releas~
ing the “emergency OFF” system must not cause uncontrolled or undefined re-
starts.
Caution
. Installation of connection and signal lines must be such that inductive and
capacitive interferences do not affect the automation functions.
● Installation of automation systems and their operating components must be
such that they are sufficiently protected against accidental activation.
. Appropriate safety measures must be provided on the 1/0 coupling of the
hardware and software to prevent a line or wire break from causing undefined
states in the automation system.
s – Iv
@Siemens AG

Notes on Safetv
6Active and Passive Errors of an Automation System
● Depending on the task to be performed by an electronic automation system, both active and
passive errors can bedangerous errors. In a drive control system, for example, theactive error
is usually dangerous since it can cause the drive to be switched on. In contrast, a passive error
in a message function can prevent a dangerous operating state from being reported.
● The distinction between possible errors and their classification as dangerous or not dangerous
based on their task is
impottant to all safety measures concerning the-delivered product.
A
!
Warning
Everywhere where errors in the automation system can cause substantial pro–
petty damage or even personal injury (i.e., can be dangerous errors), additional
external measures must be taken or systems created which will ensure or force
safe operation when an error occurs (e.g., with an independent limit value
switch, mechanical locks, etc.).
7Maintenance and Repair Procedures
When measurements or tests must be performed on an active device, the specifications and in-
structions contained in accident prevention regulation VBG 4.0, and
58 “Permissible Deviations
during Work on Active Parts” in particular, must be complied with. Suitable electrical tools must be
used.
A
, Warning
/ 6 \—
●
●
●
●
●
●
Repairs on an automation system may only be performed by Siemens Service
personnel or by repair shops authorized by Siemens. When replacing parts
or components, use only parts contained in the spare parts list or listed under the
section on spare parts in this manual. Unauthorized opening and faulty repairs
can result in death or severe personal injury, and substantial property damage.
Before opening the device
always
pull the power plug or open the disconnection
switch.
When replacing fuses, use only the types specified in the technical specifications
or the maintenance instructions of this publication.
Do not throw batteries in an open fire and do not perform soldering on the body of
the battery. Danger of explosion (maximum temperature of 100° C). Do not
open or recharge lithium batteries or batteries containing mercury. When replac-
ing, use only the same types.
Always dispose of batteries or accumulators at a special waste collection point.
Use of monitors:
Faulty work (particularly changes in the high–voltage or installation of another
type of picture tube) can result in increased emission of X–rays. A device which
has been thus modified no longer meets certification criteria and may not be op-
erated.
-1
Theinformation inthis manual ischecked atregular intervals toensurethatdata iscurrent and correct. Theinformation can be
changed at anytime without special notification. The manual contains information which is protected by copyright. Repro-
duction or translation into other languages is prohibited without prior written permission from Siemens.
@ Siemens AG s–v

ENVIRONMENTAL
PROTECTION
IN ACTION
Information Concerning
Packaging Material/Notes on Disposal
Dear Customer !
Our high–quality products cannot reach you safely without effective protective packaging. The size of
the packaging is kept to an absolute minimum.
All our packaging materials are harmless to the environment and can be disposed over without danger.
Wood is not chemically treated.
Cardboard is made primarily of waste paper which can then be torn up and given to a waste paper col-
lection.
Sheeting is made of polyethylene (PE), tapes of polypropylene (PP) and CFC–free padding of foamed
polystyrene
(PS).
These materials are pure hydrocarbons and can be recycled. Please dispose of these valuable secon-
dary raw materials at a recycling center.
Recycling saves raw materials and cuts down on the amount of refuse.
Ask your city administration for the address of the recycling center nearest you to dispose of packing
materials and discarded devices.
Thank you for your help !

SIEMENS
Warning
Risks involved in the use of so–called SIMATIC-compatible modules of non–Siemens manu-
facture
“The manufacturer of a product (SIMATIC in this case) is under the general obligation to give warning of
possible risks attached to his product. This obligation has been extended in recent court rulings to in-
clude parts supplied by other vendors. Accordingly, the manufacturer is obliged to observe and recog-
nize such hazards as may arise when a product is combined with products of other manufacture.
For this reason, we feel obliged to warn our customers who use SIMATIC products not to install
so-called SIMATIC–compatible modules of other manufacture in the form of replacement or
add-on modules in SIMATIC systems.
Our products undergo a strict quality assurance procedure. We have no knowledge as to whether
outside manufacturers of so–called SIMATIC– compatible modules have any quality assurance at all or
one that is nearly equivalent to ours. These so–called SIMATIC– compatible modules are not marketed
in agreement with Siemens; we have never recommended the use of so–called SIMATIC–compatible
modules of other manufacture. The advertising of these other manufacturers for so–called
SIMATIC–compatible modules wrongly creates the impression that the subject advertised in
periodicals,
catalogues or at exhibitions had been agreed to by us. Where so–called
SIMATIC–compatible modules of non–Siemens manufacture are combined with our SIMATIC
automation systems, we have a case of our product being used contrary to recommendations. Because
of the variety of applications of our SIMATIC automation systems and the large number of these
products marketed worldwide, we cannot give a concrete description specifically analyzing the hazards
created by these so–called SIMATIC–compatible modules. It is beyond the manufacturer’s
capabilities to have all these so–calledSIMATIC– compatible modules checked for their effect on our
SIMATIC products. If the use of so–called SIMATIC– compatible modules leads to defects in a SIMATIC
automation system, no warranty for such systems will be given by Siemens.
In the event of product liability damages due to the use of so–called SIMATIC–compatible modules,
Siemens is not liable since we have taken timely action in warning users of the potential hazards in-
volved in so–called
SIMATIC–compatible modules. ”

R 11/92
Table of Contents
Table of Contents
1
1.1
1.2
1.3
1.4
1.5
2
2.1
2.2
2.3
3
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
3.10
4
4.1
4.2
4.3
4.4
4.5
4.6
5
5.1
5.2
5.3
5.4
5.5
5.6
General Function Description
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-1
Short Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–1
Application Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 –2
HardwareDescription . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 –3
Process Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 –12
CommunicationwiththeSIMATIC S5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 –22
Hardware Settings
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1
Location ofthe Setting Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–1
Settingthe DILSwitches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–3
Settingthe Plug-lnJumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–7
SoftwareSettings
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–1
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–1
Select Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–4
Load Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–5
Interrupt Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–7
CounterVaiueRegister(CVR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–9
lnterruptEnable Register (lFR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–11
lnterruptlnformationRegister(llR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–12
Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–14
Parameter Registersand Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–16
Overviewofthe RegisterAddresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–18
Interrupt Processing
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–1
Whatlslnterrupt Processing? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–1
Interrupt Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–2
Reaction Times During Interrupt Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–4
InterruptSources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–6
GuidelinesforlnterruptProcessing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–8
Hysteresisofthe lnterruptValue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–9
CommissioningtheCounter Module
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-1
Commissioning Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–1
Startup Behaviorofthe Counter Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–3
RESET Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–4
Evaluation ofthe Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–5
Changing the Direction
ofCounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–8
Overviewofthe Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–9
IP281 EquipmentManual
@SiemensAG 1992, OrderNo: 6ES5998-0KP21

Tab/e of Contents
R 11/92
6
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
7
7.1
7.2
7.3
7.4
7.5
8
8.1
8.2
8.3
8.4
8.5
8.6
8.7
Operating Modes and Functions
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–1
CounterSettings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–2
Autonomous Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–7
CombinationOperating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–17
Handling theCounters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–23
Gate Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–30
Method ofOperation of the Digital Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–34
Block Circuit Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–40
Programming Example
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7–1
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7–1
Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7–4
Cyclic Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7–5
InterruptProcessing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7–6
Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7–7
Technical Specifications
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-1
CounterInputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8–1
Counting Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8–2
PowerSupply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8–3
Environmental Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8–4
lnWhich Slots CantheCounter Module Be Operated? . . . . . . . . . . . . . . . . . . . . . 8–5
Connection
Cablesfor incremental Encoders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8–6
Requirements onthelnputSignals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8–10
Definition ofTerms
Index
II
lP281 EquipmentManual
@SiemensAG1992, 0rderNo:6ES5 998-0KP21

. .
E- I
Guidelines for Handling Electrostatic Sensitive
Devices (ESD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
E–I
. .
S- I
Notes on SafetyfortheUser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
s–I

Introduction
Setup of the Manual
This equipment manual is intended as an aid to installing and operating the 1P 281 module.
Before starting to work with the module, take thetimeto Iookthrough this equipment manual. You
can start by looking up passages which are of particular interest to you. The goal is to obtain an
overview of the information provided.
The individual sections are self–contained and provide blocks of information on the following sub-
jects,
– Installation
– Commissioning
– Handling
Sections 2,3 and 6 contain information on special tasks which you will have to perform when pre-
paring the module for operation.
Abbreviations
Abbreviations which are not part of everyday usage are written out in full the first time they appear.
In addition, a list of all abbreviations is provided in the “Definition of Terms” at the end of the manual.
Cross References
Cross references to parts of other sections are not made unless the repetition of facts would re-
quire too much space and it can be assumed that the description at another location is sufficient.
Only the applicable subsection number is given for cross references to parts of other sections.
Example:
(+ section 2.1)
1P 281 Equipment Manual
@ Siemens AG 1992, Order No: 6ES5 998-0KP21

Principle of Operation of a Counter Module
Counting is primarily the acquisition and summation of events. In the world of electronics, this is
the summation of pulses. Two directions of counting are available.
Counting up
Binary
(Decimal =4)
When counting up, the pulses are added (to a start value in some cases).
This can be used, for example, for simple acquisition of a piece count.
Counting down
Starting with a start value which you have stored in a register (memory loca-
tion) of the 1P 281, the counter is decremented by the number of input pul-
ses.
I
I
Down
counter
m
5 input pulses
WI 000011111 I
I
(Decimal = 15)
2
Binary
L
0001 0100
(Decimal = 20)
This can be used, for example, to count out an exact number of pieces and
then package them. The counter is provided with an output signal here
which can be used, for example, to close a valve when counter status zero
is reached,
1P 281 Equipment Manual
@SiemensA(31992, order No: 6ES5998-0KP21

Counting with
It is often necessary to link the pulses (depending on other input variables)
software start
starting at a defined point in time, and then use this group information to
(or software stop)
start or stop the counter.
Input pulses
up
counter
t J software start
(Decimal =2)
This can be used, for example, if you know that the characteristics (differ-
ences in shape, color, material or other differences) of the first products will
be different from the serial product.
Counting with
If a hardware signal is to start a high–speed counting procedure directly
hardware
from the system (i.e., from the process), this signal is best applied directly to
gate control
the gate of the counter. This permits the counter to be started without
loading the S5 cycle.
Input pulses
1
Counter
—
A ::’~5
‘ATE
Binary
0000
0011
signal
(Decimal =3)
A defined stop of the counting procedure can also be performed with the
gate.
1P 281 Equipment Manual
@Siemens AG 1992, order No: 6E.S5 998-I)KP21
3

Application Areas of the 1P 281
The 1P 281 counter module permits the acquisition and conditioning of counting pulses up to a
counting frequency of 250
kHz.
Why is such a conditioning module required when STEP5 programmable counters are already
available for all programmable controllers?
These software counters have limits. To count 50 Hz pulses, for example, the programmable con-
troller must process the counter program portion at time intervals of less than 10 msec. (Twice
the “processing frequency” is required since the software counter must also acquire the falling
edge of the counting signal in order to be able to recognize the rising edge.)
– Multiple calling of the counter program portion (with direct access to the periphery)
– Counting input as interrupt input
When a software counter is used as an interrupt program, the sampling time limit of the signal
is shortened to the run time of the longest individual block. This applies particularly to the use of
input module 432. The delay time of the input filter of this module can be shortened to 0.3 msec.
Theoretically, this makes it possible to acquire frequencies up to approximately 1.5 kHz. However,
the operating system cannot recognize the pulses since the interval between two signal edges is
too small (i.e., all counting pulses are not acquired).
Considering the above arguments, software counters and the
1P 281 conditioning counter module
can be used for the following application areas.
Low frequencies are counted with software counters.
Higher frequencies (up to 250 kHz) are
counted with special counter modules such as the 1P 281.
There is no
clearcut boundary between the two methods (between 50 Hz and several 100 Hz).
4
1P 281 Equipment Manual
@ Siemens AG 1992, Order No: 6ES5 998-0KP21

The 1P 281 offers additional advantages which speak for the use of this module.
●
●
●
●
Depending on the degree of expansion, the module is equipped with one or two counters. The
counters can be used together or separately.
The external addressing of counting gate inputs offers additional ways to start and stop the
counters.
Start values can be specified for the counters by the S5 program. The point in time at which
these values are loaded in the counters can be specified by the S5 program or directly by the
external signals.
Each counter can report events (e.g., overflow or end of counting). This message can be both
an interrupt to the programmable controller, and an external hardware output.
The counter module is used as the connecting element between high–speed events in the pro-
cess, and the program in the programmable controller.
Use of the
1P 281 counter module requires that the following steps be performed.
1. Analysis of
the counting
task
c
2. Hardware
settings (jum-
pers and DIL
switches)
9
3. Parame–
Process
1P 281 Equipment Manual
@ .%TIWflS AG 1992, Order No: 6ES5 998-0KP21