The Siemens 6ES72350KD220XA0 is an analog input/output module specifically designed for the S7200 series PLC, suitable for scenarios in industrial automation systems that require highprecision analog signal acquisition and control. The following is a detailed analysis from aspects such as technical parameters, functional characteristics, application scenarios, and purchase suggestions:
- Core Technical Parameters
- Signal TypeSiemens 6ES72315QA300XB0 module
Input Channel: 4 analog input (AI) channels, supporting ±10V DC voltage signals, with a resolution of 12 bits and an accuracy of ±0.5% FS (Full Scale).
Output Channel: 1 analog output (AO) channel, supporting ±10V DC voltage signals, with a resolution of 12 bits.
- Power Supply Requirements6ES71425AF000BA0 Siemens
24V DC power supply (the module’s own power consumption is approximately 30mA).
- Communication InterfaceSiemens 1FL60342AF211LH1 Servo Motor
Directly connected to the CPU module through the bus interface (flat cable) of the S7200 PLC, without the need for additional communication protocol configuration.
- Physical CharacteristicsSiemens converter 6SE64402UD420GA1
Dimensions: 14.4×22.0×12.3cm, with a weight of approximately 0.33kg, suitable for compact installation environments.
- Certification and ComplianceSiemens V20 Inverter 15KW of Model 6SL32105BE315UV0
Complies with CE certification, and some suppliers mention 3C certification (the specific model needs to be confirmed).
- Functional Characteristics and Application Scenarios
- Functional CharacteristicsChint converters (NVF2G18.5/TS4 or NVF2G18.5/PS4
Highprecision Conversion: A 12bit resolution ensures accurate acquisition and output of analog signals, suitable for monitoring and control of continuous variables such as temperature, pressure, and flow.
Flexible ConfigurationAB Inverter 25BD043N114
The input channels can select the range (such as ±5V, ±10V) through DIP switches.
The output channels support directly driving actuators (such as regulating valves, frequency converters) with voltage signals.
Antiinterference Design: Builtin filter circuit to reduce electromagnetic interference (EMI) in industrial environments.
Fault Diagnosis: Quickly locate module anomalies through LED indicators (such as the SF fault light).
- Typical Application Scenarios
Industrial Automation
Closedloop temperature control of production lines (such as injection molding machines, reactors).
Pressure monitoring and regulation of hydraulic systems.
Process Control
Liquid level and pH value monitoring and control of pumps and valves in water treatment plants.
Collection of electrical parameters (such as voltage, current) in energy management systems.
Experimental Equipment
Laboratory data collection (such as sensor signal recording).
III. Installation and Configuration Guide
- Hardware Installation
Module Connection
Directly insert the EM235 module into the expansion slot of the S7200 PLC, and connect it to the CPU module through a flat cable (such as CPU224, CPU226).
Ensure that the wiring is firm to avoid signal interference or module damage caused by looseness.
Signal Wiring
Analog Input
Voltage signal: Connect the sensor output (such as ±10V) to the AI channel, and ground the shielding wire at one end.
Current signal: An external 250Ω resistor is required (such as converting 420mA to 15V).
Analog Output
Directly connect to the actuator (such as the AI terminal of the frequency converter), and avoid longdistance wiring.
Power Supply Connection
The 24V DC power supply needs to be independently powered, and avoid sharing the ground with the power supply for power devices.
- Software Configuration (Taking STEP 7Micro/WIN as an Example)
- Channel Definition
Configure the type (voltage/current) and range of the analog channels in the PLC programming software.
Example: Set AIW0 as a ±10V input and AQW0 as a ±10V output.
- Data Processing
Convert the analog value (such as AIW0) to engineering quantities (such as temperature, pressure) through the MOV instruction.
Example:
- Output Control
Send the analog value to the actuator through AQW0.
- Purchase and Alternative Solutions
- Market Status
Supply Situation: This model has been discontinued (discontinued in October 2017), and is currently supplied as spare parts with limited inventory.
Price Range
Brand new original: Consult wa: 8613811255435 (there are large differences among different channels).
- Alternative Models
Direct Replacement
6ES72350KD220XA8 (CN version): It has exactly the same functions as the original model, supports the Chinese programming environment, and can be directly replaced.
Upgraded Replacement
Analog modules of the S71200 series (such as SM 1234)
Supports more channels (such as 8AI/2AO), higher resolution (16 bits), and is compatible with the TIA Portal programming environment.
Requires replacing the CPU and programming software, suitable for new projects or system upgrades.
- Fault Troubleshooting and Maintenance
- Common Faults and Solutions
No Signal Input
Check the power supply of the sensor, wiring, and range settings.
Test whether there is voltage in the AI channel (measure between AIx and AGND with a multimeter).
Abnormal Output
Confirm whether the power supply and wiring of the actuator are correct.
Check whether the output value of AQW0 is within a reasonable range (such as 032000 corresponding to ±10V).
- Longterm Maintenance
Regularly 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.
If using a secondhand module, it is recommended to conduct functional tests (such as calibrating input and output).
The installation of the Siemens 6ES72350KD220XA0 module (EM235) needs to combine hardware connection and software configuration. The following are detailed steps and precautions:
- Hardware Installation: Physical Connection and Wiring Specifications
- Module Fixing and Expansion Connection
Installation Environment Requirements
Install vertically in the control cabinet and avoid horizontal placement, which may affect heat dissipation.
Reserve at least 50mm of heat dissipation space and keep away from strong interference sources such as frequency converters and transformers.
DIN Rail Installation Steps (Reference)
- CPU Installation
Open the DIN clamp at the bottom of the CPU, snap it onto the rail, and push the clamp back to lock it.
- Expansion Module Installation
Remove the bus connector cover on the right side of the CPU (gently pry it with a screwdriver).
Pull out the clamp at the bottom of the EM235 module, hang it on the rail, and slide it to the left until the bus connector is fully engaged with the CPU.
Push the clamp back, and a “click” sound indicates that the installation is in place.
Panel Installation
Fix it through the installation holes at the top and bottom of the module using M4 screws, and ensure that the screw torque is moderate (approximately 0.5N·m).
- Main Circuit Wiring
Power Supply Connection
24V DC Input: Connect the positive pole (L+) of the external 24V power supply to the `L+` terminal of the module, and connect the negative pole (M) to the `M` terminal.
Note: The power supply needs to be independently powered, and avoid sharing the ground with the power supply for power devices.
Analog Input (AI) Wiring (Reference)
Voltage Signal (±10V)
Twowire system: The sensor needs an external 24V power supply, connect the positive pole of the signal to `AIx+`, and the negative pole to `AIx`.
Current Signal (420mA)
- Antiinterference Measures
Shielding and Grounding (Reference)
Use a doubletwisted shielded wire for the signal cable, and ground the shielding layer at one end through the grounding terminal (PE) on the module side.
Establish an equipotential body: Connect the metal frame of the control cabinet, the PE terminal of the module, and the grounding end of the sensor through a copper busbar, and the grounding resistance < 10Ω.
Wiring Specifications
Lay the analog signal wires separately from the power wires (with a spacing > 30cm), and avoid parallel routing.
For longdistance signals (>50m), a signal isolator needs to be installed.
- Software Configuration: Parameter Setting and Programming Implementation
- Hardware Configuration and Parameter Initialization
DIP Switch Setting (Reference)
Configure the input range (such as setting SW1SW3 to `ON` to select ±10V) through the 8bit DIP switch on the side of the module.
If the module is installed in the first expansion slot on the right side of the CPU, the address remains the default; if it is installed in other positions, it needs to be manually allocated in the programming software.
- Programming Implementation (Taking STEP 7Micro/WIN as an Example)
Reading Analog Input
Writing Analog Output
Analog Filtering
Enable the filtering function in the “System Block”, and set the number of samples (such as 8 times) and the dead zone (such as ±5%).
- Function Testing and Calibration
Noload Test
Disconnect the load, force the output of a fixed value through the programming software (such as AQW0 = 16000 corresponding to 5V), and measure whether the output terminal is normal with a multimeter.
Load Test
Connect the actuator, gradually adjust the output value, and observe whether the device runs smoothly.
Calibration
If high precision is required, a highprecision signal source needs to be used for calibration (such as when the input is 5V, the module should output 16000).
III. Precautions and Common Problem Troubleshooting
- Safe Operation
Poweroff Operation: Before installing or removing the module, cut off the power supply of the PLC and all related devices, and wait for 5 minutes (to ensure that the capacitor is discharged).
Wiring Inspection
Check the power supply voltage, signal polarity, and whether the wiring is loose with a multimeter before powering on.
- Fault Troubleshooting
| Phenomenon | Possible Reasons | Solutions |
| The SF light of the module is on | Wiring error, signal overrange, or module failure | Check the wiring, reset the DIP switch, and replace the module |
| Abnormal output (such as jumping) | Interference, poor grounding, or programming error | Optimize the wiring, check the grounding, and debug the program |
| No response to input | Sensor failure, incorrect range setting, or channel not enabled | Test the sensor, confirm the DIP switch, and check the program logic |
- Alternative Solutions and Upgrade Suggestions
Direct Replacement
6ES72350KD220XA8 (CN version): It has the same functions as the original model, supports the Chinese programming environment, and can be directly replaced.
Upgraded Replacement
SM 1234 module of the S71200 series: Supports more channels (such as 8AI/2AO), higher resolution (16 bits), and is compatible with TIA Portal programming, but requires replacing the CPU and software.
The installation of the EM235 module needs to strictly follow the principles of “reliable hardware connection, accurate software configuration, and optimized antiinterference in the environment”. Through reasonable grounding, wiring, and parameter setting, highprecision transmission of analog signals can be ensured. For systems in longterm operation, it is recommended to regularly check the wiring terminals and the status of the module, and perform functional calibration when necessary to maintain the stability of the equipment. If higher performance or extended functions are required, it is preferred to upgrade to the S71200/1500 series.
The Siemens 6ES72350KD220XA0 is a classic analog module. Although it has been discontinued, due to its high costeffectiveness and stability, it is still widely used in the field of industrial automation. For new projects, it is recommended to give priority to upgrading to the S71200 series; for the maintenance of existing systems, attention should be paid to the supply situation of spare parts and compatibility. When purchasing, be sure to choose a reliable channel and reserve enough testing time to ensure the normal operation of the module.
