Siemens 6AV6355-1AA47-7CM3 OP 77A

SKU: 6AV6355-1AA47-7CM3 Category: HMI & Display Brand: Siemens

Description
Additional information

The Siemens 6AV6355-1AA47-7CM3 is an operator panel belonging to the SIMATIC HMI OP 77A series, designed for human-machine interface applications in industrial automation environments. This unit is part of Siemens' SIMATIC HMI product line and provides a compact, key-operated interface for machine-level operator control and monitoring. It is intended for use with Siemens SIMATIC S7 PLCs and compatible controllers.

The OP 77A features a monochrome LCD display with a resolution of 128 x 64 pixels and a membrane keypad for operator input, eliminating the need for a touchscreen. It supports MPI and PROFIBUS DP communication interfaces, enabling direct integration into existing Siemens automation networks. The panel is configured using WinCC flexible software and supports basic alarm management, recipe handling, and trend display functions. It operates on a 24 V DC supply and is rated IP65 on the front face for protection against dust and water ingress.

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 glove use or contamination. The panel is frequently used in conjunction with SIMATIC S7-200, S7-300, and S7-400 PLCs for local operator control tasks.

Technical Specifications

Display Type	Monochrome LCD
Display Resolution	128 x 64 pixels
Input/Operating Voltage	24 V DC
Communication Interface	MPI, PROFIBUS DP
IP Rating (Front)	IP65
Operating Temperature	0 °C to 50 °C
Storage Temperature	-20 °C to 60 °C
Relative Humidity	10 % to 90 % (non-condensing)
Configuration Software	WinCC flexible
Input Method	Membrane keypad
Series/Product Family	SIMATIC HMI OP 77A
Certifications	CE, UL
Mounting	Panel mounting

Common Error Codes & System Events

Event ID: 1000: No connection to the PLC or controller. Communication link between the OP 77A and the configured controller cannot be established.
Check MPI or PROFIBUS DP cable connections and termination resistors. Verify the PLC address settings match the configuration in WinCC flexible.
Event ID: 1003: Communication timeout. The panel has lost communication with the PLC during operation.
Inspect the communication cable for damage or loose connectors. Verify PLC is powered and running. Check network address configuration.
Event ID: 10000: Project download error. The configuration project could not be transferred to the panel.
Verify the PC-to-panel connection cable is correct. Ensure WinCC flexible version is compatible with the panel firmware. Retry the download.
Event ID: 10001: Insufficient memory. The project being downloaded exceeds the available memory on the panel.
Reduce the project size by removing unused screens, alarms, or recipes. Check panel memory specifications against project requirements.
Event ID: 20000: System startup error. The panel failed to complete its boot sequence correctly.
Perform a factory reset by holding the appropriate key combination during power-on. Re-download the project configuration after reset.
Event ID: 40000: Alarm buffer overflow. The number of pending alarms has exceeded the panel's alarm buffer capacity.
Acknowledge and clear existing alarms. Review the alarm configuration in WinCC flexible to reduce unnecessary alarm triggers.
Event ID: 2521: Incorrect panel firmware version. The firmware on the device is incompatible with the loaded project.
Update the panel firmware using the ProSave tool to a version compatible with the WinCC flexible project version.

Frequently Asked Questions

Which PLCs are compatible with the OP 77A panel?

The OP 77A is compatible with SIMATIC S7-200, S7-300, and S7-400 PLCs via MPI or PROFIBUS DP interfaces. It can also communicate with S7-200 via a direct PPI connection.

What software is used to configure the 6AV6355-1AA47-7CM3?

The panel is configured using Siemens WinCC flexible software. The appropriate version must be used to ensure compatibility with the panel firmware.

What is the supply voltage for this operator panel?

The OP 77A operates on a 24 V DC supply voltage.

Does the OP 77A support recipe management?

Yes, the OP 77A supports basic recipe management, allowing operators to store and transfer parameter sets between the panel and the connected PLC.

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

The front face of the OP 77A is rated IP65, providing protection against dust ingress and low-pressure water jets.

Troubleshooting

Display remains blank after power on

Check the 24 V DC supply voltage at the panel power connector. Verify the supply is within the specified voltage range and that the connector is fully seated.

Restore correct 24 V DC supply. If supply is confirmed correct, inspect the internal fuse and replace if blown. If the display remains blank, the panel may require repair or replacement of the display module.

Panel shows 'No connection to PLC' message continuously

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

Replace or reseat the communication cable. Correct the network address settings in WinCC flexible to match the PLC configuration. Ensure the PLC is powered and in RUN mode.

Project download fails from PC to panel

Confirm the correct transfer cable is being used (PC-PPI or USB-to-MPI adapter as applicable). Check that the panel is in transfer mode before initiating the download.

Set the panel to transfer mode via the Start Center menu. Use the correct cable and COM port settings in WinCC flexible. Update panel firmware via ProSave if version mismatch is detected.

Keypad buttons are unresponsive

Check for physical damage to the membrane keypad. Attempt to navigate menus using multiple keys to determine if the fault is isolated to specific buttons or the entire keypad.

If individual keys are unresponsive, the membrane keypad assembly requires replacement. If all keys are unresponsive, perform a panel reset and re-download the project. Persistent faults indicate a hardware failure requiring panel repair.

Panel reboots repeatedly or fails to complete startup

Check the 24 V DC supply for voltage drops or instability under load. Inspect the project configuration for errors that may cause a runtime fault during startup.

Stabilize the power supply and ensure adequate current capacity. Perform a factory reset and re-download a validated project. If rebooting persists with no project loaded, the panel hardware requires service.

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