EM 253 Position Module Programming Wizard
 Generates the PLC code from user’s inputs.
 Actually makes motion configurations easy!
 Allows user to complete the entire EM253 motion
module setup parameterization in just minutes.
 Included with the PLC Programming SW
 No add-on tools to purchase
 Also includes a Control Panel online interface
to optimize and adjust after the wizard
configuration has been downloaded
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 1
March 2002
Tutorial for Configuring the EM253 Position Module

PART 1: System Settings

PART 2: Machine (Drive) Data

PART 3: Setting Reference Point Search (RPS) Sequence

PART 4: Profile Definitions

PART 5: Wizard Results (Data Areas and PLC Code )

PART 6: EM253 Control Panel

PART 7: EM253 Configuration FAQ’s
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 2
March 2002
Launch the Position Control Wizard
 Launch the wizard from the
icon in the Tools menu
 The following slides take you through each EM253 wizard screen, explaining all the
input parameters, their meaning, and the significance of each one.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 3
March 2002
PART 1: System Settings
Select the EM 253 Configuration
PLC on-board PTO/PWM
PLC with EM 253 Module
F1
Press F1 for help on any Wizard screen.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 4
March 2002
PART 1: System Settings
Intelligent Module Rack Position
If connected to online PLC,
Press ‘Read Modules’ button to
automatically read intelligent
module’s rack position.
Manually setting the Intelligent Module Rack Position (in offline configurations):
Example:
Digital
1st
Analog
CPU
Digital
I/O
CPU
I/O
Physical Position:
-
0
1
2
3
Intelligent Module Number:
-
-
1
-
3
EM253 Analog EM253
I/O
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
EM253
I/O
2nd
EM253
Intelligent Modules include: EM 241, EM 253 and EM277
Slide 5
March 2002
PART 1: System Settings
Select a Measurement System
A measurement system is
selected by the user, based
on the user’s preference.
Engineering Unit Selections:
 inch
 foot
 millimeter
 centimeter
 degree
 radian
 any user-defined unit
The default ‘units’ are based on the
project’s ‘Regional Settings’ from
the Micro/WIN Options menu.
 The measurement system, Engineering Units or Number of Pulses, selected on this screen is
used throughout the wizard configuration.
 The motor’s Data Sheet specifies the pulses per revolution.
 Specifying units is convenient because the wizard handles all conversions for the user.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 6
March 2002
PART 1: System Settings
Advanced I/O Options (1 of 3)
EM253
LED’s:
STP
RPS
LIM -
LIM +
Activation
Level
Settings
Inputs:
STP
RPS
LMT -
LMT +
Module Reference
Settings:
High - a logic 1 will be read when current is flowing in the input.
Low - a logic 1 will be read when there is no current flow in the input.
A logic 1 level is always interpreted as meaning the limit has been reached. The module LED’s
will be ON if there is current flow to the corresponding input, regardless of the active level
configured.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 7
March 2002
PART 1: System Settings
Advanced I/O Options (2 of 3)
Input Filter Time for EM inputs
(applies to LMT+, LMT-, STP)
Filter Time for the RPS input
Selection Range:
 0.20 – 12.80 millisecond
 ‘None’ is also an option
Input Filter Time is delay time. The input must remain at the new state for the
duration of the delay time in order to be accepted as valid.
Purpose: The filter rejects noise impulses and forces input lines to stabilize before
the data is accepted.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 8
March 2002
PART 1: System Settings
Advanced I/O Options (3 of 3)
The Pulse Type is determined by the nature of the device.
Linear
Rotary
Left to right
CW
Right to left
CCW
Positive
Direction
Negative
Direction
An estimated 90% of users will use
devices with this default setting.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 9
March 2002
PART 2: Machine Data
Set up how the H/W inputs will Respond
Choices for each response are:
 Decelerated Stop.


Immediate Stop.
No action. (Ignore input)
These settings should not
be substituted for an
Emergency Stop (E-Stop).
Choices:
Descriptions:
Decelerated Stop : decelerates to a stop and indicates LIMIT reached (LIM activated).
Immediate Stop : stops by terminating pulses and indicates LIMIT reached (LIM activated).
No Action : ignores input condition.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 10
March 2002
PART 2: Machine Data
Use the Motor’s Data Sheet
Certain Motor parameters are vital in setting up the next wizard screens.
You must gather information from the Motor’s Data Sheet.
Data Sheet Example:
Motor Speeds:
Max. torque
Typically found as a waveform on the data sheet:
Max. torque for
the Application
NOTE:
If it’s a guess:
-The Curve Knee
is good place to
start.
- Pick from a
approx. range
and experiment
For MAX_SPEED, on the motor’s data sheet, find:
(1) Maximum torque
(2) Determine the Max. Torque for the application
Pick a range where application will most likely work.
This is NOT the same as maximum motor torque.
(3) Speed at which that torque can be achieved
(This is the MAX_SPEED to input in wizard)
For SS_SPEED, on the motor’s data sheet, find:
(1) Start Speed (also called “Pull-in”)
(2) Stop Speed (also called “Pull-out”)
SS_SPEED is the minimum of these 2 values.
Typically, a useful SS_SPEED value is 5% to 15% of
the MAX_SPEED value.
Click for More Details
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Max.
torque
speed
Max.
Pull-in:
torque
~ 80 Step/sec. (pulses/sec)
speed
for the
application
NOTICE: As load inertia increases, the curve drops.
Slide 11
March 2002
PART 2: Machine Data
Set Motor Speeds
To achieve maximum resolution
at higher speeds, range
checking is enforced: the
EM253 selects a time-base to
work with based on the
maximum speed. With this
strategy, the EM253 calculates
and enforces a minimum speed.
Notes about SS_SPEED:
 if too high, motor can ‘stall’
or ‘overshoot’
 if too low, motor can ‘cog’.
Start-Stop Speed (SS_SPEED) is the guaranteed speed at which motor can start and stop. It
is the speed plus the application’s ‘load’ factored in.
SS_SPEED value must be greater than the minimum speed displayed from your specification of
MAX_SPEED.
Click for More Details
The SS_SPEED is a mandatory setting.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 12
March 2002
PART 2: Machine Data
Set JOG parameters (for manual debugging)
Achieved by constantly enabling the Jog command
Achieved with a 1-shot Jog instruction
- or- with one click on the Jog button
Jog Commands are enabled from (1) the Control Panel or (2) an EM253 pre-defined profile
or (3) a Micro/WIN Motion instruction (these are described in more detail in later slides).
JOG_INCREMENT is the distance you want the tool to move with each JOG Command.
JOG_SPEED is the maximum speed that can be obtained while the JOG command remains
active. When the JOG command is de-activated, the EM253 automatically executes a command
that causes the tool to decelerate until it reaches STOP.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 13
March 2002
PART 2: Machine Data
Set Acceleration & Deceleration Times
ACCEL_TIME: Time required
for the motor to accelerate from
SS_SPEED to MAX_SPEED.
DECEL_TIME: Time required for
the motor to decelerate from
MAX_SPEED to SS_SPEED
Note About Defaults:
1 second default should
work for most applications.
Typically, motors can work
with less than 1 second.
MAIN POINT TO REMEMBER:
The motor’s Acceleration & Deceleration times are strictly determined by trial and error.
Times set too short can cause the motor to stall.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 14
March 2002
PART 2: Machine Data
Acceleration & Deceleration Times
Practical Way to input the Values:
‘THEORETICAL’ vs. ‘PRACTICAL’
 Theoretically, the values could be calculated (as on data
sheet)
 ‘Trial and Error’ approach is the efficient way of setting
the values.
Data Sheets show a
(theoretical) example:
USE TRIAL & ERROR
 Approximate values should be entered on the wizard
once. Specifically, start with a large value in the wizard
setting to get the application going.
 During the start-up phase, adjust the values as needed
with the EM253 Control Panel (EM253 Control Panel is
explained later).
 Optimize these settings for the application by gradually
reducing the times until the motor starts to stall.
How the values are used by EM253:
Based on the wizard inputs for the times and motor speeds, the
EM253 calculates the Accel and Decel rates (number of pulses to
accomplish the target speed).
Click for More Details
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 15
March 2002
PART 2: Machine Data
Set ‘Jerk’ Time parameters
 Jerk time provides smoother
motion control by reducing the
“jolt” (rate of change) in
acceleration and deceleration
parts of the move profile.
 Reducing “jerk” improves
position tracking performance.
 “Jerk” time is also known as
“Jolt” or “S-Curve” profiling.
 Jerk Time can only be
applied to simple 1-step
profiles. (Profiles are
explained later).
NOTE:
A good first value for JERK_TIME is 40% of ACCEL_TIME.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 16
March 2002
PART 3: Setting RPS Sequence
Reference Point
The Reference Point (RP) is only for applications using Absolute moves (moves that are
relative to a specified RP)
If you select not to use the Reference Point, the wizard dialogs for setting RP will be skipped.
In a subsequent wizard screen, the user will select a ‘Mode’ for the tool movements.
Unlike all other modes, the Absolute ‘Mode’ is based on a Reference Point setting.
Note: ‘Homing sequence’ is a term often used interchangeably with Reference Point.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 17
March 2002
PART 3: Setting RPS Sequence
Reference Point Seek: A Working Example




Seek RPS Zone to the Right
Measure RPS Zone Width
Approach RP to the Right
50% of the RPS Zone is in the
Work Zone, RP is in its Middle
RP Seek Direction
RP Approach Direction
RPS
Active
LIMIT
Active
Work Zone
1
2
3
4
Note: This is a working example of how a RP Seek would work in an application. As described on following slides, this is only one of many RP
seek sequences available; the different RP seek sequences are selected depending on the specific application
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 18
March 2002
PART 3: Setting RPS Sequence
How the RP (Reference Point) is used
Wizard settings for RP are used in a ‘Seek Sequence’.
A ‘Seek Sequence’ is executed (is command driven) when a tool abnormally stops or
malfunctions (when the exact location of the tool is unknown).
Workspace
- LMT
+ LMT
RP Offset
Zero Position
RP
The tool is present, although it’s location is unknown
The EM253 uses pre-defined searches to locate the tool to a known position in the workspace.
The tool is located according to a RP Seek Sequence that is selected by the user (the PLC
programmer).
The wizard allows the user to select the Seek Sequence that will fit best their application, and it
enhances the optimization of the user’s system.
Click for More Details
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 19
March 2002
PART 3: Setting RPS Sequence
Reference Point ‘Seek’ Parameters
RP_FAST
RP_SLOW
Speed
RP_SEEK_DIR
RP_APPR_DIR
Direction
Click for More Details
Purpose of inputs on this screen:
RP_SLOW – search slows down as it approaches the target point, and will not miss it (~ SS_SPEED).
RP_FAST – search speeds up to expedite the search (typically this will be 2/3 the MAX_SPEED)
RP_SEEK_DIR – direction that the application’s searches generally move in most of the time; this avoids
switching directions often, which would ultimately slow down the overall search.
RP_APPR_DIR – same direction as the normal work cycle proceeds in; this reduces backlash and
provides more accuracy
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 20
March 2002
PART 3: Setting RPS Sequence
Advanced RP Options
Workspace
- LMT
+ LMT
RP Offset
Zero Position
RP
RP Offset (RP_OFFSET) is at a
fixed, constant location, at an exact
distance from the zero position.
Backlash compensation would be
used when a tool is not moved in the
same direction ( not for constant
back & forth motion).
Note: When appropriately used, Backlash compensation allows the use of a lower cost equipment (such as worm gears).
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 21
March 2002
PART 3: Setting RPS Sequence
Setting a Reference Point Search (RPS) Sequence
4 possible Seek (Mode) Sequences:
MODE 1: The reference point is where the
RPS input goes active on the approach from
the work zone side.
MODE 2: The reference point is centered
within the active region of the RPS input.
MODE 3: The reference point is located
outside the active region of the RPS input.
MODE 4: The reference point is located within
the active region of the RPS input.
The graphic shown is dependent on
your previous wizard inputs:
(a) Seek Sequence
(b) ‘Direction of RP Seek’
ZP (Zero Pulse) input count is the number of
pulses issued after the home search trigger
condition is met.
(c) RP_APPR_DIR
Note: There are 4 possible Reference Point (RP) definition. With RP_SEEK_DIR and RP_APPR_DIR settings, there are 16 different sequences.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 22
March 2002
PART 4: Profile Definitions
Setting the number of User Profiles
 A Profile is created from a set
of parameters associated with a
tool’s movement.
 A profile is shown graphically
as a function of speed and
distance (see the diagram)
A ‘Step’ is a fixed distance for a tool to be
moved, including distance covered during
acceleration & deceleration times.
One ‘Step’
Distance / Number of Pulses
 You input the number of
profiles to be defined for this
EM253 project (25 is
maximum profiles allowed)
 This Q-memory area is used
to trigger commands that get
executed by the module.
Note: The programmer defines number of profiles for the project on this screen. Parameters for each profile are specified on a subsequent screen.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 23
March 2002
PART 4: Profile Definitions
Start address for the wizard configuration data
 You input the starting
PLC memory address of
where the profile data will
be placed into the PLC
memory (34 bytes for
each profile)
-or Press ‘Suggest
Address’ button and
Micro/WIN inserts the
start address of an
unused, available area
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 24
March 2002
PART 4: Profile Definitions
Examples of ‘Workable’ Profiles
(a.) 1-Step Profile
(b.) 1-Step Profile
The only thing changing will be Accel. & Decel.
rates. At minimum, this profile requires the
Wizard profile configuration to set the ‘type’.
(c.) 4-Step Profile
Different colors represent the different steps.
(d.) 4-Step Profile
Refer to the notes in figure (a.)
These are not the only profiles allowed. There are many other combinations.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 25
March 2002
PART 4: Profile Definitions
Understanding the profile ‘Mode’ selections
0 (Zero Point)
Desired ending
position from the
Zero Point.
Zero
Point
Starting
Point
Absolute Position
Controlled by your program until another
command (such as ‘Abort’) is issued
Single-speed Continuous Rotation
Target Speed with
RPS Inactive
Desired ending
position from the
Starting Point.
Relative Position
Target Speed
RPS signals Stop
Single-speed Continuous Rotation with Triggered stop.
Target Speed with
RPS Inactive
Click for More Details
Two-speed Continuous Rotation
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 26
March 2002
PART 4: Profile Definitions
Create Profile Definition(s)
1.
Select a mode for
this profile.
2.
Input parameters to
define the step:
(a.) Target Speed
(b.) Ending Position
4.
3.
5.
Press to define
another new step in
the current profile.
Click ‘Plot Step’
button (Step appears in
the window).
Repeat 1 – 4 for
each step (up to 4
steps) in each profile.
You can assign a name
to each profile.
6.
Repeat entire
process for each new
profile definition
(max. 25 profiles)
Note: Based on the programmer inputs for ‘Target Speed’ and ‘Ending Position’ for defining the step, the resulting, calculated units of
measurement will be displayed (as read only field) beneath the input parameters.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 27
March 2002
PART 5: Wizard Results
Completing the Wizard Configuration
 The wizard screen now explains
what changes will be made to your
Micro/WIN program.
 When you complete the wizard by
clicking the ‘Finish’ prompt:
(1) the indicated changes are made
to your Micro/WIN project.
(2) The instructions are added under
the ‘Call Subroutines’ folder of the
instruction tree.
(3) A Symbol table containing
EM253 project symbols is added to
the project
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 28
March 2002
PART 5: Wizard Results
Summary : Your Inputs into Motion Wizard
This is a review of the input fields on the wizard screens:
System
Settings
Intelligent Module Position in the PLC Rack
Select Measurement System & Engineering Units
Module Response to LIM+/- Switch & Stop Input
Machine Data
Motor Speed (Starting, Maximum, Jog)
Motor Acceleration & Deceleration Times
Seek Reference
Point Settings
Reference Point Seek Speed & Direction
Advanced Reference Point settings (Optional button)
Reference Point Search Sequence
Profile Definition
& Data Areas
Number of Profiles & Address of QB Command Byte
V-memory Start Address of Data Block Locations
Profile Definitions (Mode and Steps for every profile)
Finish
Last Screen shows summary of EM253 project entries
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 29
March 2002
PART 5: Wizard Results
Review : What the Motion Wizard Generates
Data Block values
(V-memory):
60-BYTES IN
DATA BLOCK
One Q byte location is
set as the EM253
‘Command Control’
Byte:
(FOR MODULE
CONFIGURATION
SETTINGS)
Q-MEMORY BYTE
SBR’s for Motion Instructions
are placed in the Micro/WIN
Instruction tree under ‘Call
Subroutines’:
POS0_CTRL (SBR1)
POS0_MAN (SBR2)
POS0_RUN (SBR3)
40-BYTES FOR
PROFILE #1
(OPTIONAL)
40-BYTES FOR
PROFILE #2
...
A Project Symbol
Table containing
EM253 Settings:
POS0_SRATE (SBR4)
POS0_GOTO (SBR5)
POS0_DIS (SBR6)
POS0_LDOFF (SBR7)
GLOBAL
SYMBOL TABLE
CONTAINING
THE POSITION
MODULE
PARAMETERS
40-BYTES FOR
PROFILE X
(MAX: X = 25)
Multiple EM253 configurations are possible.
Each configuration will have it’s own set of
DB values.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
POS0_LDPOS (SBR8)
POS0_RSEEK (SBR9)
POS0_CLR (SBR10)
POS0_CFG (SBR11)
Each EM253 configuration created will place
a set of instructions (one for ea. module in
your rack). For example:
EM253 configuration 1 = POS0_ …
EM253 configuration 2 = POS1_ …
EM253 configuration 3 = POS2_ …
Etc.
Slide 30
March 2002
PART 5: Wizard Results
Instruction Descriptions (1 / 3)
POSx_CTRL
Control
Enables and initializes the
Position module. Ensures
that your program calls this
instruction every scan. Use
SM0.0 (Always On) as the
input for the EN parameter.
POSx_MAN
Manual Mode
Puts the EM253 module
into manual mode. This
allows the motor to be run
at different speeds or to be
jogged in a positive or
negative direction. You can
enable only one of the
RUN, JOG_P, or JOG_N
inputs at a time.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
GOTO
Commands the
Position Module to
go to a desired
location.
POSx_RUN
Run Profile
Commands the Position
module to execute the
motion operation in a
specific profile stored in
the configuration/profile
table.
Slide 31
March 2002
PART 5: Wizard Results
Instruction Descriptions (2 / 3)
POSx_RSEEK
Seek Ref Pt Position
Initiates a reference point
seek operation, using the
search method in the
configuration/ profile table.
POSx_LDOFF
Load Reference Point
Offset
Establishes a new zero position
that is at a different location
from the reference point
position.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
POSx_LDPOS
Load Position
Change the current position
value in the Position
module to a new value. You
can also use this instruction
to establish a new zero
position for any absolute
move command.
Slide 32
March 2002
PART 5: Wizard Results
Instruction Descriptions (3 / 3)
POSx_SRATE
Set Rate
Commands the Position
module to change the
acceleration,
deceleration, and jerk
times.
POSx_DIS
Turns DIS output
of EM On or Off
The POSx_DIS instruction
turns the DIS output of the
Position module on or off.
This allows you to use the
DIS output for disabling or
enabling a motor
controller.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
POSx_CLR
Pulse
CLR Output
Commands the
Position module to
generate a 50-ms
pulse on the CLR
output.
POSx_CFG
Reload
Configuration
Commands the Position
module to read the
configuration block from
the location specified by
the configuration/profile
table pointer.
Slide 33
March 2002
PART 6: Control Panel
EM 253 Control Panel (for start-up & debugging)
 Runs independently of the user’s program
 Selected as separate icon under Tools
 Verifies wiring of EM253 is correct
 Verifies EM253 is configured correctly
 Allows minor adjustments to be made to
the EM253 configuration
 Prompts user if adjustments should be
made permanent to the EM253 configuration
 PLC should be ONLINE and in STOP
mode, to perform the commands or change
parameter settings.
NOTE: An online EM253 module is required to execute the Control Panel.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 34
March 2002
PART 6: Control Panel
‘Operation’ tab
Select
Module
Command
Module
Status
Manual
Operation
Profile
Status
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 35
March 2002
PART 6: Control Panel
Profile & Module Status
EM253
Step 3
Step 2
Step 1
Examine the
individual
profiles.
Step 4
Profile
Status
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Module
Status
Slide 36
March 2002
PART 6: Control Panel
Select a Module Command
List-box of 13 Module Commands
Each command selection is different:
• Necessary fields and buttons are enabled.
• Instructions for the selected command are displayed.
Enable Manual Operation
Use Manual controls to place the
tool.
Load Reference Point Offset
(1) Use Manual controls to place the
tool at a new Zero Position. (2) Click
Execute to save this as the
RP_OFFSET .
Pulse the CLR output
Click Execute to pulse the CLR
output.
Move to An Absolute Position
Moves to a specified position at a
target speed. Before using this
command, you must have already
established the zero position.
Run a Motion Profile
(1) Type in a profile number, and (2)
click Execute. EM253 runs that
profile one time (includes all steps).
Reload Current Position
(1) Type in the position to set, and (2)
press Execute to initiate the move.
Teach a motion Profile
(1) After setting profile number and
step, (2) use Jog buttons to position
the tool, (3) then press Teach button
to save it.
Move by a Relative Amount
Move a specified distance from the
current position at a target speed
(Positive or Negative distance).
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Seek to a Reference Point
Click Execute starts the EM command
to search for a Ref. Point using the
algorithm configured for the EM253.
Activate/Deactivate DIS output
Click Execute to activate the DIS
output.
Load Module Configuration
Loads a new configuration by
commanding the EM module to read
the configuration block from the V
memory.
Reset the Command Interface
Clears the command byte for the
Position module
and sets the Done bit.
Slide 37
March 2002
PART 6: Control Panel
Manual Operation
This portion of the screen changes depending on what ‘Module Command is selected.
Determines how fast the
tool will move with
manual operations.
Determines whether tool
moves backwards or
forwards.
Click once on Jog button
for JOG_INCREMENT
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Used to reset, and set
different values while
command is running.
Used to toggle the EM253
between Start and Stop
Only possible in STOP
mode.
Hold down the Jog button
to reach JOG_SPEED.
Slide 38
March 2002
PART 6: Control Panel
‘Configuration’ tab allows real-time user inputs
Determines
whether screen
fields can be
Edited or are
Read-only
Reference
Point
Settings
NOTE:
Upon exit of the
Control Panel, the
user is prompted
about whether
changes should be
permanently written
to the EM253
configuration.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Application
Parameters
If pressed,
causes the
screen values to
be written to the
PLC data block.
Slide 39
March 2002
PART 6: Control Panel
‘Diagnostics’ tab has Module Information
Module
Information
Displays information
about EM253 such
as:
- Position of EM in
I/O Chain
- Module Type
- Firmware Version
- Command Byte
Whenever
Error(s) occur,
the Diagnostics
Tab flashes:
“New Error In
Module”
This Error
indicator is then
visible from any
screen in the
Control Panel.
All Error codes
Are found in
The S7-200
Systems
Manual.
- Error Codes
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 40
March 2002
PART 7: EM253 Configuration FAQ’s
EM 253 Configuration FAQ’s (1/2)
QUESTION: If user has already finished configuring the EM253 module with the wizard, how can subsequent
changes be made to the configuration?
ANSWER: Re-run the wizard, or use the EM253 control panel.
QUESTION: Can the PLC programmer program the EM253 without using the EM253 wizard?
ANSWER: Yes, although this is not recommended because of the number of required data fields.
QUESTION: If user has selected engineering units, can the user change to different engineering units or to
pulses/revolutions later in the configuration?
ANSWER: Yes, although no conversion will take place. However, on a re-edit of a configuration, the user cannot
change between engineering units and pulses.
QUESTION: If user has more than one EM253 module, can the wizard be run for each module?
ANSWER: Yes. The user can run the wizard multiple times as long as sufficient memory is available. The
programmer must set the start addresses so that multiple EM253 configurations do not overwrite one another.
QUESTION: A user has two EM253 modules and the user needs to copy the first configuration in order to
make minor modification for the second EM253. How can the configuration be copied?
ANSWER: When existing configurations are present, the wizard can move a configuration to another slot. No copy
is provided.
QUESTION: Can a PLC use the on-board PTO/PWM and the EM253 at the same time?
ANSWER: Yes. The wizard is run twice (once for the PLC’s onboard PTO and once for EM253).
QUESTION: Can the Accel. and/or Decel. Times be changed ‘on the fly’? How?
ANSWER: Yes. From the EM523 Control Panel, or by using the POSx_SRATE motion instruction.
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 41
March 2002
PART 7: EM253 Configuration FAQ’s
EM 253 Configuration FAQ’s (2/2)
QUESTION: Does the EM253 support ‘micro-stepping’?
ANSWER: Yes, up to the maximum speed of the module (200 KHz). To configure it in the wizard, increase the
pulses required for one revolution.
QUESTION: Can each profile have a different mode?
ANSWER: Yes.
QUESTION: If I have 2 profiles that need to be run back-to-back, will there be a delay between the 2 profiles?
ANSWER: Yes, since it must stop & then start back up; length depends on: (1) whether the profile is ‘buffered’ and
(2) PLC scan time.
QUESTION: Is it possible to enter a RP (Ref. Point) without a “home sequence”?
ANSWER: Yes. An instruction, POSx_LDPOS, is available for doing this.
QUESTION: Can I synchronize 3 devices in one system (PLC, motion data, position counter) ?
ANSWER: Yes. This would be done with the PLC logic (not done automatically with the EM253).
QUESTION: Can I use an HMI to control or monitor my motion module status?
ANSWER: Yes. Use HMI to control memory area associated with the EM253 inputs and outputs, or the motion
instructions’ inputs and outputs.
QUESTION: Can I link the execution of more than 1 profile without stopping?
ANSWER: No. The EM253 must stop after each profile. A profile always starts with motor stopped, and always
ends with the motor stopped.
QUESTION: Where can I find out more details and information about configuring the EM253 ?
ANSWER: The new S7-200 Systems Manual (Chapter 9) covers the EM253 Position Module
(Manual Order No.: 6ES7 298--8FA22--8BH0)
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 42
March 2002
The End.
The End.
Thanks for your Attention.
For further information about the EM253:
Refer to the S7-200 Systems Manual,
Chapter 9
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 43
March 2002
Use the Motor’s Data Sheet – More Details
Selection of the MAX_SPEED parameters is not always easy. Users typically do not know what the
‘Torque for the application’ is going to be.
If you have no idea, then guess by picking a value near on the waveform’s ‘knee’, and then adjust it later.
“MOST IMPORTANT” is shown in bold on the slides that discuss (1) Motor speeds and (2)
Acceleration/Deceleration times.
Why? These parameters are most critical in getting the EM253 set up to work properly.
In general, if a user can set these parameters with reasonable data for his/her application, then the
EM253 will basically work with the application.
All other parameters are also important in getting a system to work optimally. However, in the initial start
up phase, the parameters (marked as ‘MOST IMPORTANT’) are most critical.
If customer has a motor whose data sheet parameters are not sufficient for the what the application needs,
then the customer probably needs a bigger motor.
If the “start-speed” is given in ‘steps/sec’, and user is using units other than pulses/sec, then user will need
to convert from pulses/sec to units, such as inches.
Example:
If 1000 pulses = 1 inch
Then 80 step/second will be 80/1000 inches/second
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Return To Slides
Slide 44
March 2002
Set Motor Speeds – More Details
The SS_SPEED is mandatory.
All other calculations (In subsequent screens like when specifying Profiles, Jog parameters,
Accel/Decel parameters, etc.) the SS_SPEED is used by the module in calculating and making the
programmed moves.
When you set MAX value, the EM253 selects the range for you as seen in the MIN_SPEED, which
is a read-only field. It means that the pulse rate will not go any lower than the calculated
MIN_SPEED.
SS_SPEED cannot be lower than MIN_SPEED, and this is enforced by a range check performed
by the wizard.
The EM253 module supports the following ranges:
12 PPS to 2K PPS
60 PPS to 10K PPS
300 PPS to 50K PPS
1200 PPS to 200K PPS
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Return To Slides
Slide 45
March 2002
Acceleration & Deceleration Times – More Details
It is theoretically possible to calculate the Acceleration/Deceleration times from inertia,
friction torque, etc. as shown on a motor’s data sheet.
However, 90%-100 % of average users are not able to obtain or calculate these values. (It
is too scientific, data such as ‘inertia’ is unknown, etc. )
This is where the Micro/WIN Wizard & Control Panel makes it easy for the users!!!
As stated on the slide, the practical way to set up the Acceleration/Deceleration times is
with “trial and error” in the initial set up:
• Start with a large value.
• After you get the application going, start gradually reducing the time until motor stalls.
Return To Slides
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 46
March 2002
How the RP (Reference Point) is used – More Details
Absolute Move - A position move relative from a specified reference point or "zero position."
Relative Move - (incremental move) where the position move is relative from the current position. The two settings
(INITIAL & APPROACH) can be set opposite. For instance, ‘initial’ direction can be opposite the ‘approach’
direction.
Relative Move - (incremental move) where the position move is relative from the current position.
NOTE: The slides show ‘linear’ motion (‘rotary’ motion is also possible with EM253)
WORKSAPCE AREA: EM253 applications take place within a Workspace area.
BOUNDARY LIMITS: The workspace has boundary LIMITS on each side.
The LIM boundaries are typically sensor devices that provide inputs to the EM253.
The application reacts to LIM inputs based on the LIM responses.
ABSOLUTE MOVES:
To perform an Absolute Move, the important positions are:
1.
A known Tool Position (not shown) that can be in or out of the workspace area.
2.
A Reference Point (RP) is used as the target of the tool’s movement (for initialization).
3.
A Zero Point (ZP) is at a fixed, constant location
Why does seeking need to be time efficient?
Seeking is typically used between an application’s transition between builds, or at the beginning of work cycles, etc. The
seek sequence reduces time and effort needed to place the work tool in the correct starting position. Otherwise,
manual intervention to move the tool could be required, which would require extra man power and would cost more
time.
Return To Slides
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 47
March 2002
Reference Point ‘Seek’ Parameters – More Details
The tool will start the seek at a faster speed because seeking needs to be time efficient. This is called
RP_FAST. It is used in positioning the tool (As Quickly As Possible) near the RP.
Since the tool can only stop at certain speeds, it must be going that speed when it reaches the RP. This
is called the RP_SLOW (NOTE: This speed must be less than SS_SPEED).
The two settings (INITIAL & APPROACH) can be set opposite. For instance, initial direction can be
opposite the approach direction.
SEEK BEGINS with:
RP_SEEK_DIR - For each seek, will the initial seek direction be positive (right) or negative (left)?
RP_FAST – (consider motor size & SS_SPEED) How fast should seek be set?
During the SEEK :
(1) The tool begins to move. Tool will move towards the RP -or- towards a LIM, depending on set
direction.
(2) If tool reaches a LIM, tool movement reverses and continues in the other direction towards the RP.
(3) Tool speed is reduced (to the settings below) as it approaches the RP and prepares to stop.
SEEK FINISHES with:
RP_APPR_DIR - will the seek direction be positive (right) or negative (left)?
RP_SLOW – (consider motor size & SS_SPEED) how fast should seek be set?
APPLICATION NOTE: Normally, with linear moves, the application direction and seek direction will be opposite. With
rotary moves, they will be the same.
Return To Slides
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 48
March 2002
The profile ‘Mode’ selections – More Details
Execution of commands shall cause the module to perform the motion operation specified in the MODE field of the Profile
Block indicated by the command_code portion of the command. The specifications for Interactive Block motion operations are
not cached, so they are read each time that the module receives this command.
In absolute position mode the motion profile block shall define from one to four steps with each step containing both the
position (POS) and speed (SPD) that describes the move segment. The POS specification represents an absolute location,
which is based on the location designated as reference point. The direction of movement is determined by the relationship
between the current position and the position of the first step in the profile. In a multi-step move, a reversal of direction of
travel shall be prohibited and shall result in an error condition being reported.
In relative position mode the motion profile block shall define from one to four steps with each step containing both the
position (POS) and the speed (SPD) that describes the move segment. The sign of the position value (POS) shall determine
the direction of the movement. In a multi-step move, a reversal of direction of travel shall be prohibited and shall result in the
reporting of an error condition.
In the single-speed, continuous speed modes, the position (POS) specification shall be ignored and the module shall
accelerate to the speed specified in the SPD field of the first step. One Mode is used for positive rotation and the other mode
is used for negative rotation.
In the single-speed, continuous speed modes with triggered stop, the module shall accelerate to the speed specified in
the SPD field of the first step. If and when the RPS input becomes active, movement shall stop after completing the distance
specified in the POS field of the first step. One Mode is used for positive rotation and the other mode is used for negative
rotation.
In two-speed, continuous speed modes the binary value of the RPS input selects one of two continuous speed values as
specified by the first two steps in the profile block. One Mode is used for positive rotation and the other mode is used for
negative rotation. The SPD controls the speed of movement. The POS values shall be ignored in this mode. The following
table defines the relationship between the inputs and the step within the profile block.
Return To Slides
STEP 7-Micro/WIN V3.2 EM253 Motion Wizard
Slide 49
March 2002