Siemens 6AV6355-1AA47-7DG0 OP 77A

€ 955,52

SKU: 6AV6355-1AA47-7DG0 Category: HMI & Display Brand: Siemens

Description
Additional information

The Siemens 6AV6355-1AA47-7DG0 is an operator panel belonging to the SIMATIC HMI OP 77A series, designed for human-machine interface applications in industrial automation environments. This compact panel operator unit is part of Siemens' SIMATIC HMI product line and provides a key-based interface for process monitoring and control. It is intended for use with Siemens SIMATIC S7 and other compatible PLC families.

The OP 77A features a monochrome LCD display with a resolution suited for text and basic graphic visualization, along with a membrane keypad for operator input. It supports MPI and PROFIBUS DP communication interfaces, enabling direct integration with SIMATIC S7-200, S7-300, and S7-400 controllers. The unit operates on a 24 V DC supply and is configured using Siemens WinCC flexible or STEP 7 Micro/WIN engineering software, allowing tag-based data exchange and alarm management.

The OP 77A is commonly deployed in machine-level control panels across manufacturing, packaging, and process industries where a cost-effective, robust operator interface is required. Its compact form factor and keypad-based operation make it suitable for environments where touchscreen panels are impractical due to gloves, dust, or vibration. The panel is typically mounted in control cabinet doors or machine enclosures with a standard panel cutout.

Technical Specifications

Display Type	Monochrome LCD
Display Size	4 inches
Input Voltage	24 V DC
Power Consumption	Max. 5 W
Communication Interface	MPI, PROFIBUS DP
Operating Temperature	0 °C to +50 °C
Storage Temperature	-20 °C to +60 °C
Relative Humidity	10% to 90% (non-condensing)
IP Protection Rating	IP65 (front)
Mounting	Panel mounting
Series/Product Family	SIMATIC HMI OP 77A
Certifications	CE, UL
Configuration Software	WinCC flexible, STEP 7 Micro/WIN

Common Error Codes and System Events

Event ID: 10000: Communication error between the OP 77A and the connected PLC. The panel cannot establish or maintain a connection to the controller.
Check MPI or PROFIBUS DP cable connections and termination resistors. Verify the PLC address settings match the panel configuration. Ensure the PLC is in RUN mode.
Event ID: 10001: Connection to the configured PLC was interrupted during operation.
Inspect communication cables for damage or loose connectors. Verify network topology and bus termination. Restart the panel and PLC if the connection is not restored automatically.
Event ID: 20000: Configuration or project data on the panel is missing or corrupted.
Re-download the project from WinCC flexible or STEP 7 Micro/WIN to the panel. Ensure the correct project version is used for this hardware variant.
Event ID: 40000: System memory or internal storage error detected on the panel.
Perform a factory reset of the panel and re-transfer the project. If the error persists, the internal memory may be faulty and the unit should be sent for repair.
Event ID: 50000: Power supply voltage is outside the permissible range.
Measure the 24 V DC supply at the panel connector. Ensure the supply voltage is within the specified range and that the power supply unit is functioning correctly.
Event ID: 60000: Operating system or firmware error detected during panel startup.
Attempt a panel restart. If the error recurs, update the panel firmware using the appropriate Siemens tool. If unsuccessful, the panel may require hardware service.
Alarm: Tag Read Error: The panel is unable to read a configured tag from the PLC. The tag address may be incorrect or the PLC data block is unavailable.
Verify the tag address configuration in WinCC flexible. Confirm the corresponding data block or memory area exists in the PLC program and is accessible.

Frequently Asked Questions

Which PLCs are compatible with the OP 77A (6AV6355-1AA47-7DG0)?

The OP 77A is compatible with Siemens SIMATIC S7-200, S7-300, and S7-400 PLCs via MPI or PROFIBUS DP interfaces. It can also communicate with S5 controllers using appropriate protocol adapters.

What software is used to configure and program the OP 77A?

The OP 77A is configured using Siemens WinCC flexible (for S7-300/400) or STEP 7 Micro/WIN (for S7-200). Projects are transferred to the panel via MPI cable or a PC adapter.

What is the supply voltage requirement for the 6AV6355-1AA47-7DG0?

The panel requires a 24 V DC power supply. The supply must be within the specified tolerance range to ensure reliable operation.

What is the front panel protection rating of the OP 77A?

The OP 77A has an IP65 protection rating on the front face, making it resistant to dust and water jets when correctly installed in a panel cutout.

Can the OP 77A display graphical images or only text?

The OP 77A supports basic text and simple graphic elements on its monochrome LCD display. It is not intended for complex graphical visualization, which would require a higher-end SIMATIC HMI panel.

Troubleshooting

Display remains blank after power is applied

Check the 24 V DC supply voltage at the panel power connector using a multimeter. Verify that the supply polarity is correct and that the voltage is within specification.

Correct any wiring errors and ensure the power supply output is stable at 24 V DC. If the supply is correct and the display remains blank, the internal power supply or display backlight may be faulty and the unit should be inspected for repair.

Panel shows 'No connection to PLC' or communication error on startup

Verify the MPI or PROFIBUS DP cable is securely connected at both the panel and PLC ends. Check that bus termination resistors are correctly placed at both ends of the network segment.

Replace or reseat the communication cable. Confirm the PLC station address and baud rate match the panel project configuration. Re-download the project if settings were recently changed.

Panel keys are unresponsive or intermittently respond

Inspect the membrane keypad for physical damage, contamination, or wear. Test each key systematically to identify whether the issue is isolated to specific keys or affects the entire keypad.

Clean the keypad surface with a dry cloth. If keys remain unresponsive, the membrane keypad assembly may need replacement. Contact a qualified repair technician to replace the keypad module.

Project transfer from PC to panel fails

Check the PC adapter or MPI cable connection between the engineering PC and the panel. Verify that the correct COM port and transfer settings are selected in WinCC flexible or STEP 7 Micro/WIN.

Try a different USB or serial port on the PC. Ensure the panel is in transfer mode before initiating the download. Update the PC adapter drivers if necessary and retry the transfer.

Alarm messages are not displayed on the panel during operation

Verify that alarm tags are correctly configured in the WinCC flexible project and that the corresponding PLC bit addresses are mapped correctly. Check that the PLC program is setting the alarm bits as expected.

Correct any tag address mismatches in the project configuration and re-download to the panel. Confirm the PLC logic is functioning correctly by monitoring the alarm bits in STEP 7 or WinCC flexible online mode.

Condition	Repair, Used, Refurbished, New in box (sealed)