In a standard PROFINET setup, the Siemens PLC works as the PROFINET IO Controller and the ET 200SP interface module works as the PROFINET IO Device. The physical station must match the hardware configured in TIA Portal, and the online-assigned PROFINET device name must match the configured name before normal cyclic I/O data exchange starts.
1. ET 200SP PROFINET communication — overview
SIMATIC ET 200SP is a compact distributed I/O platform that places digital, analog and technology modules close to field devices. Instead of wiring every sensor and actuator back to the PLC cabinet, the PLC exchanges cyclic process data with the remote station over PROFINET.
IO Controller
IO Device
The communication path is therefore simple: PLC → PROFINET network → ET 200SP interface module → local I/O modules → field devices. TIA Portal combines network configuration, station hardware, I/O addressing and online diagnostics in one engineering project.
2. Hardware and engineering requirements
Before opening TIA Portal, confirm the installed hardware and the field I/O list. A typical station requires the PLC, an ET 200SP PROFINET interface module, suitable BaseUnits, the required digital/analog/technology modules, a server module where applicable, 24 VDC supplies and industrial Ethernet cabling.
| Item | What to verify | Why it matters |
|---|---|---|
| PLC | Correct CPU order number, firmware and PROFINET interface | TIA Portal configuration must match the real controller. |
| ET 200SP interface | Exact interface module type/order number and supported firmware | Wrong catalog selection can create configuration or download mismatches. |
| I/O modules | Module type, slot order, channel count and signal type | The offline station must follow the installed module sequence. |
| BaseUnits / wiring | Compatible BaseUnit, supply grouping, sensor/actuator wiring | Many field faults are electrical or BaseUnit-related rather than network faults. |
| Network | Unique device name, planned IP address/subnet, switch/cable path | A duplicate IP or wrong device identity prevents reliable commissioning. |
3. PROFINET device name vs IP address
This is the most important concept in many ET 200SP commissioning problems. The PROFINET device name is the logical identity used by the IO Controller to identify its IO Device. The IP address supports IP-based communication and engineering access, but it does not replace the PROFINET device name.
| Parameter | Purpose | Commissioning rule |
|---|---|---|
| PROFINET device name | Identifies the ET 200SP IO Device to the PLC | The name configured in TIA Portal and the name assigned online to the physical device must match. |
| IP address | IP communication and engineering access | Use the intended PN/IE subnet and avoid duplicate addresses. |
| MAC address | Physical Ethernet interface identity | Useful when identifying an uncommissioned device before the correct PROFINET name is assigned. |
When several identical ET 200SP stations are present, use TIA Portal's Flash LED function during device-name assignment to confirm that you are naming the correct physical station.
4. TIA Portal configuration — step by step
- Create or open the project. Add the exact S7-1200 or S7-1500 CPU used on the machine.
- Add the ET 200SP station. Select the exact PROFINET interface module from the hardware catalog.
- Build the station hardware. Insert the ET 200SP modules in the same left-to-right slot order as the real station and confirm compatible BaseUnits.
- Open Devices & networks. Connect the PLC PROFINET interface and the ET 200SP interface to the intended PN/IE subnet.
- Set the configured PROFINET device name. Use a clear, unique plant naming convention such as
et200sp_line1_01. - Set the IP configuration. Apply the machine or plant IP plan and make sure no device uses a duplicate address.
- Check I/O addresses. Review the automatically assigned input/output ranges and adjust only when your project standard requires a defined address plan.
- Create PLC tags. Map physical channels to descriptive names such as
Conveyor_PE_01orMotor_01_RunCmd. - Compile hardware and software. Resolve configuration errors before going online.
- Assign the PROFINET device name online. From Network view or Online & diagnostics, select the correct PG/PC interface, identify the physical ET 200SP, use Flash LED if needed and assign the configured name.
- Download the configuration to the PLC. Put the machine in an approved commissioning condition and follow the site's safety procedure.
- Go online and verify data exchange. Confirm the ET 200SP appears healthy, then monitor real inputs and test outputs only when safe and authorized.
5. ET 200SP I/O address mapping in the PLC
Each configured ET 200SP channel is assigned a PLC input or output address. In production projects, the recommended engineering practice is to create meaningful symbolic PLC tags and use those names in the program. This makes commissioning, maintenance and later migration easier.
| Signal | Typical PLC data area | Recommended symbolic tag | Program use |
|---|---|---|---|
| Digital sensor | Input bit | Tank_HighLevel | Interlock / sequence condition |
| Motor contactor command | Output bit | Pump_01_RunCmd | Manual/auto output mapping |
| 4–20 mA transmitter | Input word | Pressure_Raw | Scaling to engineering units |
| Analog command | Output word | VFD_SpeedRef_Raw | Scaled speed/reference output |
The actual absolute addresses depend on your selected modules and configured address ranges. Do not copy addresses from another project without checking the current Device view.
6. Commissioning checklist before declaring the station healthy
- PLC and ET 200SP are powered correctly.
- Ethernet link is present at both ends.
- Correct PG/PC network adapter is selected.
- PLC and ET 200SP are on the intended PN/IE network.
- Configured and physical PROFINET device names match.
- No duplicate IP address exists.
- Offline module order matches the physical station.
- Order numbers and firmware are compatible.
- No unresolved station/module/channel diagnostic remains.
- PLC tags point to the expected I/O addresses.
- Inputs change correctly with field devices.
- Outputs are tested only under approved safe conditions.
7. Common ET 200SP PROFINET faults and troubleshooting
| Symptom | Likely area | Recommended checks |
|---|---|---|
| ET 200SP not found online | Power / cable / PG-PC interface | Verify 24 VDC, link LEDs, Ethernet cable/switch and selected PC adapter. Use Accessible devices. |
| Station visible but no normal I/O exchange | PROFINET identity | Compare configured device name with the name stored in the physical interface module; reassign when different. |
| Station/module mismatch | Hardware configuration | Compare interface module, I/O module order numbers, firmware and slot sequence with the real rack. |
| One channel has bad value / diagnostic | Field wiring / parameterization | Check BaseUnit, sensor supply, signal type, input range, channel parameters and field wiring. |
| Correct device, wrong field signal in logic | I/O mapping | Cross-check channel address, PLC tag address and the program tag used in LAD/FBD/SCL. |
| Intermittent communication | Network quality / installation | Inspect connectors, switch ports, cable routing, shielding/grounding practices and network diagnostics. |
For diagnostics, start at the physical layer and move upward: power → cable/link → device visibility → device name → IP/subnet → hardware match → channel diagnostics → PLC tag mapping. This order prevents unnecessary hardware replacement.
8. Practical training exercise
Build a small ET 200SP station with at least one digital input and one digital output module. Configure it in TIA Portal, assign the PROFINET name, download the PLC and verify I/O. Then create faults one at a time in a controlled training setup and record the TIA Portal diagnostic message for each condition.
- Disconnect the Ethernet cable and compare online diagnostics.
- Change or remove the device name, then observe the communication result.
- Disconnect one field sensor and compare the PLC tag with the electrical condition.
- Where the training hardware permits it, create a safe module/channel diagnostic and identify it in Online & diagnostics.
- Restore the station and verify that cyclic I/O returns to normal.
This exercise teaches more than configuration: it builds a repeatable troubleshooting method for maintenance and commissioning engineers.
9. Frequently asked questions
Can S7-1200 communicate with ET 200SP?
Yes. An S7-1200 CPU with a suitable PROFINET interface can operate ET 200SP as distributed I/O when the station is configured in TIA Portal and the PROFINET device name is assigned correctly.
Why is the ET 200SP PROFINET device name important?
The configured device name is the identity used by the PROFINET IO controller. The name stored in the physical ET 200SP interface module must match the name configured in the TIA Portal project before normal I/O data exchange can start.
Do the PLC and ET 200SP need IP addresses in the same subnet?
For normal engineering access and the typical PROFINET network used in a small machine or training setup, configure the PLC and ET 200SP on the intended PN/IE subnet and use a consistent IP plan without duplicate addresses.
How are ET 200SP signals used in the PLC program?
TIA Portal assigns input and output addresses to the configured channels. Create meaningful PLC tags for these addresses and use the tags in LAD, FBD or SCL instead of programming with unexplained absolute addresses.
How do I diagnose an ET 200SP remote I/O fault?
Check power and Ethernet link first, then open Online & diagnostics and compare the online station with the configured hardware. Verify the PROFINET device name, IP/subnet, module order, article numbers, firmware compatibility, BaseUnits, channel parameters and field wiring.
What should I check when an ET 200SP module shows a diagnostic fault?
Open the device and module diagnostics in TIA Portal and identify whether the message is related to network communication, module mismatch, missing module, channel wiring, supply voltage or parameterization before replacing hardware.
10. Official Siemens references
Recommended technical references
For exact menu names, firmware-specific behavior and supported functions, verify the current Siemens documentation for your installed CPU and ET 200SP interface module.