Siemens 6AV6355-1AA47-7FA4 OP 77A

€ 407,65

SKU: 6AV6355-1AA47-7FA4 Category: HMI & Display Brand: Siemens

Description
Additional information

The Siemens 6AV6355-1AA47-7FA4 is an operator panel belonging to the OP 77A series within the Siemens SIMATIC HMI product family. This compact panel operator unit is designed for machine-level human-machine interface applications, providing a straightforward interface for process monitoring and control. It is part of the SIMATIC HMI Basic Panels generation, intended for use with Siemens SIMATIC S7 and other compatible controllers.

The OP 77A features a monochrome LCD display with a resolution of 160 x 80 pixels and a membrane keypad for operator input, eliminating the need for a touchscreen. It supports MPI and PROFIBUS DP communication interfaces, enabling direct connection to SIMATIC S7-200, S7-300, and S7-400 PLCs. The panel is configured using WinCC flexible software and offers a compact, robust housing suitable for panel mounting with an IP65 front protection rating.

The OP 77A is widely deployed in manufacturing, packaging, and process automation environments where a cost-effective, reliable operator interface is required at the machine level. Its compatibility with the SIMATIC controller range and straightforward configuration make it suitable for applications such as conveyor systems, pump stations, and general-purpose machine control where basic status display and parameter entry are needed.

Technical Specifications

Display Type	Monochrome LCD
Display Resolution	160 x 80 pixels
Input/Operating Voltage	24 V DC
Power Consumption	3 W (typical)
Communication Interface	MPI, PROFIBUS DP
IP Protection Rating (Front)	IP65
IP Protection Rating (Rear)	IP20
Operating Temperature	0 °C to +50 °C
Storage Temperature	-20 °C to +60 °C
Relative Humidity	10% to 90% (non-condensing)
Mounting	Panel mounting
Series/Product Family	SIMATIC HMI OP 77A
Configuration Software	WinCC flexible 2005 or higher
Certifications	CE, UL

Common Error Codes & System Events

Event ID: 10000: Communication error between the HMI panel and the connected PLC controller.
Check MPI/PROFIBUS DP cable connections and termination resistors. Verify the PLC address settings match the HMI project configuration and that the PLC is in RUN mode.
Event ID: 10001: Connection to the PLC has been interrupted or lost during operation.
Inspect the communication cable for damage or loose connectors. Confirm the baud rate and station address settings are consistent between the HMI and PLC.
Event ID: 20000: Project download error — the configuration project could not be transferred to the panel.
Verify the PC-to-panel connection (MPI or serial cable). Ensure the WinCC flexible project is compiled without errors before attempting the transfer.
Event ID: 40000: System memory low — available memory on the panel is insufficient for the loaded project.
Reduce the project size by removing unused screens, tags, or graphics. Ensure the project is optimized for the OP 77A memory capacity.
Event ID: 50000: Operating system or firmware error detected on the panel.
Perform a panel reset and reload the firmware using the appropriate Siemens ProSave tool. If the error persists, the panel may require service or replacement.
Event ID: 60000: Configuration mismatch — the loaded project is not compatible with the current panel firmware version.
Update the panel firmware to the version required by the WinCC flexible project, or recompile the project targeting the installed firmware version.
Event ID: 70000: Power supply voltage out of range — the 24 V DC supply is outside acceptable limits.
Measure the supply voltage at the panel connector. Ensure the supply is within the 20.4–28.8 V DC range and check for loose wiring or an inadequate power supply unit.

Frequently Asked Questions

Which PLCs are compatible with the OP 77A (6AV6355-1AA47-7FA4)?

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 S7-200 via the PPI protocol.

What software is used to configure the OP 77A?

The OP 77A is configured using Siemens WinCC flexible 2005 or a later version. Projects are compiled on a PC and downloaded to the panel via MPI or a serial connection.

What is the supply voltage requirement for this panel?

The panel requires a 24 V DC supply, with an acceptable operating range of approximately 20.4 V DC to 28.8 V DC.

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

The front face of the OP 77A carries an IP65 protection rating, making it suitable for panel-mount installations where dust and water spray protection is required.

Does the OP 77A support touchscreen input?

No, the OP 77A does not feature a touchscreen. Operator input is performed exclusively via the integrated membrane keypad.

Troubleshooting

Display remains blank after power on

Check the 24 V DC supply voltage at the panel power connector using a multimeter. Verify the supply is within the 20.4–28.8 V DC range and that all connections are secure.

Restore the correct supply voltage or replace the power supply unit if faulty. If the supply is correct and the display remains blank, the internal power supply board or display module may require replacement.

Panel shows 'No connection to PLC' message

Verify the MPI or PROFIBUS DP cable is correctly connected and terminated at both ends. Check that the PLC station address and baud rate configured in the HMI project match the actual PLC settings.

Correct any address or baud rate mismatches in the WinCC flexible project and re-download. Replace the communication cable if it is damaged, and ensure termination resistors are correctly placed on the bus.

Project download fails from WinCC flexible

Confirm the PC-to-panel connection cable (MPI adapter or PC/PPI cable) is functioning and recognized by the PC. Check that the panel is in transfer mode and that no firewall or driver issue is blocking communication.

Switch the panel to transfer mode manually via the panel menu. Reinstall the communication adapter drivers on the PC if necessary, and ensure the WinCC flexible project compiles without errors before attempting the download.

Operator keypad buttons are unresponsive

Test each key systematically in the panel's service or startup menu if accessible. Inspect the membrane keypad connector inside the panel for corrosion or disconnection.

Clean the keypad connector contacts and reseat the connector. If individual keys remain non-functional, the membrane keypad assembly should be replaced.

Panel repeatedly restarts or resets during operation

Monitor the supply voltage for dips or instability under load. Check the panel for signs of overheating, such as high ambient temperature or blocked ventilation around the enclosure.

Stabilize the 24 V DC power supply and ensure adequate ventilation in the control cabinet. If restarts persist with a stable supply, reload the firmware using ProSave and check for project errors that may cause software exceptions.

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