Siemens 6AV6355-1AA47-7DF2 OP 77A

€ 1.995,00

SKU: 6AV6355-1AA47-7DF2 Category: HMI & Display Brand: Siemens

Description
Additional information

The Siemens 6AV6355-1AA47-7DF2 is an operator panel belonging to the SIMATIC HMI OP 77A series, manufactured by Siemens as part of their SIMATIC HMI Basic Panels product line. This compact panel operator unit is designed for straightforward machine-level human-machine interface tasks, providing operators with a reliable means of monitoring and controlling industrial processes. The OP 77A is a key-operated panel featuring a text-based display, suited for applications where a full graphical interface is not required.

The OP 77A panel features a 4-line STN LCD display capable of showing alphanumeric text and basic symbols, with a membrane keypad for operator input including function keys and system keys. It supports MPI and PROFIBUS DP communication interfaces, enabling direct integration with Siemens SIMATIC S7-200, S7-300, and S7-400 PLCs. The unit operates on a 24 V DC supply and is configured using Siemens WinCC flexible software. It offers a compact, panel-mount design with an IP65 protection rating on the front face, making it suitable for use in environments where dust and water ingress protection is required.

The SIMATIC OP 77A is widely deployed in manufacturing, machine building, and process automation environments where basic operator control and status monitoring are needed at the machine level. It is commonly found on packaging machinery, conveyor systems, and general-purpose industrial machines where cost-effective HMI solutions with reliable PLC connectivity are prioritized. Its compatibility with the established SIMATIC S7 controller family makes it a practical choice for system integrators working within the Siemens automation ecosystem.

Technical Specifications

Display Type	STN LCD, 4-line text display
Display Colors	Monochrome
Input Voltage	24 V DC
Voltage Tolerance	19.2 V DC to 28.8 V DC
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
Configuration Software	WinCC flexible 2005 or higher
PLC Compatibility	SIMATIC S7-200, S7-300, S7-400
Certifications	CE, UL, cULus

Common Error Codes and System Events

Event ID: 10000: Communication error between the HMI panel 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 HMI project configuration. Ensure the PLC is powered and in RUN mode.
Event ID: 10001: Connection to PLC interrupted during operation. The panel lost communication with the configured controller.
Inspect the communication cable for damage or loose connectors. Check bus termination and cable shielding. Restart both the HMI panel and the PLC and monitor for recurrence.
Event ID: 20000: Project download error. The transfer of the HMI project from the configuration PC to the panel failed.
Verify the transfer cable and PC interface settings. Ensure the panel is in Transfer mode before initiating download. Check WinCC flexible project compatibility with the panel firmware version.
Event ID: 40000: System memory low or configuration data error. The panel detected an issue with stored project data or available memory.
Reload the HMI project from WinCC flexible. If the problem persists, perform a factory reset of the panel and re-download the project.
Event ID: 50000: Firmware version mismatch. The firmware on the panel is incompatible with the downloaded project version.
Update the panel firmware to the version required by the WinCC flexible project. Use the Siemens ProSave tool or WinCC flexible to perform the firmware update.
Event ID: 70000: Tag or variable access error. The HMI panel cannot read or write a configured tag in the PLC.
Verify the tag addresses in the WinCC flexible project match the actual PLC data block or memory addresses. Check PLC program for deleted or modified variables.

Frequently Asked Questions

Which PLCs are compatible with the OP 77A panel?

The OP 77A is compatible with Siemens SIMATIC S7-200, S7-300, and S7-400 PLCs via MPI or PROFIBUS DP communication interfaces.

What software is used to configure the OP 77A?

The OP 77A is configured using Siemens WinCC flexible 2005 or later versions. Projects are downloaded to the panel via the MPI interface or a dedicated transfer cable.

What is the supply voltage for the OP 77A?

The panel requires a 24 V DC supply voltage, with an acceptable operating range of 19.2 V DC to 28.8 V DC.

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

The front face of the OP 77A carries an IP65 protection rating, making it resistant to dust ingress and low-pressure water jets when correctly panel-mounted with the supplied gasket.

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

The OP 77A is a text-based operator panel and does not support graphical image display. It is limited to alphanumeric characters and basic symbols on its 4-line monochrome LCD.

Troubleshooting

Display remains blank after power is applied

Check the 24 V DC supply voltage at the panel power connector using a multimeter. Verify the supply is within the 19.2 V to 28.8 V DC range. Inspect the power connector for loose or reversed wiring.

Correct any wiring faults and ensure a stable 24 V DC supply. If the supply is confirmed correct and the display remains blank, the internal power supply or display unit may be faulty and the panel should be sent for repair or replacement.

Panel displays communication error or cannot connect to PLC

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 bus. Confirm the PLC address and baud rate settings in the HMI project match the physical PLC configuration.

Correct any address or baud rate mismatches in the WinCC flexible project and re-download. Replace damaged cables or connectors. Ensure only the correct nodes have bus termination enabled.

Project download from PC to panel fails

Confirm the panel is set to Transfer mode before initiating the download. Check the transfer cable connection between the PC and the panel MPI port. Verify that the WinCC flexible project version is compatible with the installed panel firmware.

Switch the panel to Transfer mode via the Start Center menu. Replace the transfer cable if faulty. Update the panel firmware using ProSave if a version mismatch is identified, then retry the project download.

Function keys do not respond or produce incorrect actions

Check the WinCC flexible project for correct function key assignments. Test each key individually in the panel's built-in key test mode if available. Inspect the membrane keypad for physical damage or contamination under the keys.

Correct any incorrect key assignments in the project and re-download. If the membrane keypad is physically damaged or keys are unresponsive despite correct configuration, the keypad membrane will need to be replaced.

Panel repeatedly restarts or enters an error loop after startup

Attempt to access the Start Center during boot by pressing the appropriate key combination. Check whether the stored project data is corrupted by observing any error messages during startup. Verify the supply voltage is stable and free from voltage dips.

Perform a factory reset via the Start Center to clear corrupted project data, then re-download the project from WinCC flexible. If voltage instability is suspected, install a suitable 24 V DC stabilized power supply with adequate current capacity.

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