Siemens 6ES7253-1AA22-0XA0 (EM253)

Siemens 6ES72531AA220XA0 (EM253) is a singleaxis positioning expansion module specifically designed for the S7200 series PLC. It is mainly used for the openloop position control of stepper motors or servo drivers and supports a pulse output frequency of up to 200kHz. The following is a detailed analysis from aspects such as technical parameters, functional characteristics, installation configuration, application scenarios, and maintenance suggestions:Siemens 6ES72350KD220XA0

1. Core Technical Parameters
2. Signal TypesSiemens 6ES72315QA300XB0 module

Digital Inputs (DI): 5 channels, supporting functions such as STP (Emergency Stop), RPS (Reference Point Switching), LMT+ (Forward Limit), LMT (Reverse Limit), and ZP (Origin Signal). The input delay (0.2~12.8ms) can be set through DIP switches.

Pulse Output (PTO): 2 differential signal channels (P0+/、P1+/), supporting RS422/RS485 or 5V DC output. The pulse frequency can reach up to 200kHz, which is used to control the direction and speed of the motor.

Control Outputs: 2 channels (DIS, CLR), used for enabling the driver and clearing errors.

2. Power Requirements6ES71425AF000BA0 Siemens

Module Power Supply: 24V DC (independently supplied externally, with a maximum current of 130mA).

Backplane Bus: 5V DC (provided by the CPU, with a maximum current of 190mA).

3. Physical CharacteristicsSiemens 1FL60342AF211LH1 Servo Motor

Dimensions: 71.2×80×62mm, with a weight of approximately 190g. It supports DIN rail installation or panel fixation.

4. Certification and ComplianceSiemens converter 6SE64402UD420GA1

It complies with CE certification and supports the RoHS directive

1. Functional Characteristics and Typical Applications
2. Core FunctionsSiemens V20 Inverter 15KW of Model 6SL32105BE315UV0

Highprecision PositioningChint converters (NVF2G18.5/TS4 or NVF2G18.5/PS4

It supports motion modes such as absolute position, relative position, and homing. The motion envelope (such as speed, acceleration, and target position) can be defined through the “Position Control Wizard” in STEP 7Micro/WIN.AB Inverter 25BD043N114

It has a builtin pitch compensation function to eliminate mechanical transmission errors.

Flexible ConfigurationSiemens 6EP1 2520AA01 chain power supply

The pulse equivalent (such as 0.01mm displacement corresponding to 1 pulse) and the electronic gear ratio (the transmission ratio between the motor and the load) can be set.

It supports dynamically modifying parameters such as acceleration and deceleration time and maximum speed.

Safety Mechanism

The emergency stop input (STP) can immediately cut off the pulse output to protect the equipment.

The limit switches (LMT+/) and the origin signal (ZP) ensure that the mechanical stroke is within a safe range.

2. Typical Application Scenarios

Industrial Automation

Packaging machinery (such as material sorting, label pasting).

CNC machine tools (such as tool positioning, worktable movement).

Logistics Equipment

Path control of automatic guided vehicles (AGVs).

Precise positioning of storage shelves.

Experimental Equipment

Driving of stepper motors on laboratory platforms (such as spectrometers, pipettes).

III. Hardware Installation and Wiring Specifications

1. Module Connection

Communication with CPU

It is directly connected to the expansion slot on the right side of the CPU (such as CPU224, CPU226) through the expansion bus (flat cable) of the S7200.

The module address is automatically assigned according to the installation position (for example, the address of the first expansion module is 0).

Power Connection

The positive pole (L+) of the 24V DC power supply is connected to the `L+` terminal of the module, and the negative pole (M) is connected to the `M` terminal.

Ensure that the power supply is independently supplied and avoid sharing the ground with the power supply of power equipment.

2. Signal Wiring

Stepper Motor Control

Pulse Output

P0+/ is connected to the pulse signal of the driver (such as A+/), and P1+/ is connected to the direction signal (such as B+/).

For differential signals, a twisted pair shielded wire should be used, and the shielding layer should be grounded at one end.

Limit and Origin Signals

LMT+/ is connected to the normally closed contacts of the limit switch, and ZP is connected to the normally open contact of the origin switch.

The input signal should share the ground with the module (M terminal).

Servo Driver Control

If the driver supports the pulse + direction mode, the wiring method is the same as that of the stepper motor.

If it supports analog quantity setting (such as a 010V speed command), an additional analog output module (such as EM253) needs to be connected.

3. Antiinterference Measures

Shielding and Grounding

A twisted pair shielded wire should be used for the signal cable, and the shielding layer should be grounded through the `PE` terminal of the module.

Establish an equipotential body: Connect the metal frame of the control cabinet, the PE terminal of the module, and the grounding end of the motor through a copper busbar.

Wiring Specifications

The pulse signal wire should be laid separately from the power wire (with a spacing of > 30cm), and parallel routing should be avoided.

For longdistance signals (> 50m), a signal isolator needs to be installed.

1. Software Configuration and Programming Implementation
2. Hardware Configuration and Parameter Initialization

DIP Switch Settings

The input delay (for example, setting SW1SW3 to `ON` to select 0.2ms) can be configured through the DIP switch on the side of the module.

Note: The switch setting should be carried out after powering off, and the parameters of the entire module should be unified.

Position Control Wizard

1. Open the Wizard: Select “Tools” → “Position Control Wizard” in STEP 7Micro/WIN and select “Axis 0” (the default axis of EM253).
2. Define Parameters

Pulse output mode (such as PTO), the number of pulses per motor revolution, and the electronic gear ratio.

Motion envelope: Set the target position, speed, acceleration/deceleration.

3. Generate Function Blocks: The wizard automatically generates subroutines (such as `POS0_CTRL`, `POS0_GOTO`) and data blocks (storing configuration parameters).
4. Programming Implementation

Initialization and Control Instructions

Absolute Positioning Exampl

3. Function Testing and Calibration

Noload Test

Disconnect the motor and force the output of pulses through the programming software, and verify whether the signal is normal with an oscilloscope.

Load Test

Connect the motor, gradually adjust the speed and position, and observe whether the operation is smooth.

Origin Calibration

Perform the homing operation to ensure that the position value is 0 when the ZP signal is triggered.

1. Fault Troubleshooting and Maintenance Suggestions
2. Common Faults and Solutions

2. Longterm Maintenance

Regular Inspection

Clean the dust on the surface of the module to ensure good heat dissipation.

Check whether the wiring terminals are loose to avoid poor contact.

Data Backup

Export the configuration data block through Micro/WIN to prevent parameter loss.

Spare Parts Management

This module has been discontinued (discontinued in 2015). It is recommended to reserve spare parts or upgrade to the S71200 series.

1. Alternative Solutions and Upgrade Suggestions
2. Direct Replacement

6ES72531AA220XA8 (CN version): It has exactly the same functions as the original model, supports the Chinese programming environment, and can be directly replaced.

2. Upgrade Replacement

S71200 Series Positioning Module (such as SM 1223)

It supports more axes (such as 4 axes) and higher resolution (16 bits), and is compatible with the TIA Portal programming environment.

The CPU (such as CPU 1214C) and programming software need to be replaced, but it has stronger expandability.

S71500 Series CM 12425

It supports PROFINET communication and is suitable for complex motion control networks.

VII. Summary

The EM253 module is a core component for achieving precise positioning control in the S7200 system. Its wiring and programming need to strictly follow the principles of “reliable hardware connection, accurate software configuration, and optimized environmental antiinterference”. Through reasonable parameter settings and antiinterference measures, the stable operation of stepper motors or servo drivers can be ensured. For new projects or system upgrades, it is recommended to give priority to the S71200/1500 series to obtain higher performance and longer life cycle support. When purchasing, pay attention to the discontinued status of the module, select a reliable channel, and reserve testing time.