Siemens 6AV6355-4AA00-0AA2 OP 77A

€ 1.995,00

SKU: 6AV6355-4AA00-0AA2 Category: HMI & Display Brand: Siemens

Description
Additional information

The Siemens 6AV6355-4AA00-0AA2 is the OP 77A operator panel, part of the SIMATIC HMI Basic Panels product family from Siemens. This compact operator panel is designed for straightforward machine-level human-machine interface tasks, providing a text-based display for process visualization and operator control. It belongs to the entry-level segment of the SIMATIC HMI portfolio, offering reliable performance for applications where graphical displays are not required.

The OP 77A features a 4-line text display capable of showing alphanumeric characters, along with a membrane keypad for operator input including function keys and system keys. It communicates via the MPI/PROFIBUS DP interface, enabling direct integration with SIMATIC S7-200, S7-300, and S7-400 PLCs. The panel is configured using WinCC flexible Compact or Standard engineering software, and supports alarm management, recipe handling, and simple process value display. The unit 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 widely used in manufacturing and process automation environments where cost-effective, text-based operator interfaces are sufficient. Typical applications include machine tool control panels, conveyor systems, packaging machinery, and small-scale process control installations. Its compact form factor and panel-mount design make it suitable for integration into control cabinets and machine enclosures across industries such as automotive, food and beverage, and general manufacturing.

Technical Specifications

Display Type	Text display, 4-line alphanumeric
Display Characters per Line	20 characters
Input/Operating Voltage	24 V DC
Permissible Voltage Range	19.2 V DC to 28.8 V DC
Power Consumption	Max. 4 W
Communication Interface	MPI / PROFIBUS DP (RS-485)
IP Rating (Front)	IP65
IP 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
Certifications	CE, UL, cULus
Engineering Software	WinCC flexible Compact / Standard
PLC Compatibility	SIMATIC S7-200, S7-300, S7-400

Common Error Codes & 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/PROFIBUS DP cable connections and termination resistors. Verify the PLC address and baud rate settings match the panel configuration. Ensure the PLC is in RUN mode.
Event ID: 10001: Connection to the PLC was interrupted during operation.
Inspect the communication cable for damage or loose connectors. Check network topology and bus termination. Restart the panel and PLC if the connection is not re-established automatically.
Event ID: 20000: Configuration error detected. The project loaded on the panel is incompatible or corrupt.
Re-download the project from WinCC flexible to the panel. Verify the project was compiled without errors before transfer.
Event ID: 40000: Operator panel internal error or system fault detected.
Perform a power cycle on the panel. If the error persists, perform a factory reset and re-download the project. Contact Siemens support if the fault recurs.
Event ID: 50000: Recipe data error. A recipe record could not be read or written correctly.
Check recipe configuration in WinCC flexible. Verify that recipe data areas in the PLC data blocks are correctly mapped and accessible.
Event ID: 60000: Alarm buffer overflow. The number of pending alarms exceeds the panel buffer capacity.
Acknowledge and clear existing alarms. Review the alarm configuration to reduce the number of simultaneously active alarms or increase acknowledgement frequency.
Event ID: 70000: Tag update error. One or more process tags could not be updated within the configured cycle time.
Reduce the number of tags or increase the update cycle time in the project configuration. Check PLC scan time and communication load on the MPI/PROFIBUS network.

Frequently Asked Questions

Which PLCs are compatible with the OP 77A (6AV6355-4AA00-0AA2)?

The OP 77A is compatible with SIMATIC S7-200, S7-300, and S7-400 PLCs via the MPI or PROFIBUS DP interface. It can also communicate with S7-200 via the PPI protocol depending on configuration.

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

The OP 77A is configured using Siemens WinCC flexible Compact or WinCC flexible Standard engineering software. Projects are downloaded to the panel via the MPI interface or a PC adapter cable.

What is the supply voltage for the OP 77A?

The OP 77A requires a 24 V DC supply voltage, with a permissible 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 is rated IP65, providing protection against dust ingress and low-pressure water jets, making it suitable for panel-mount installations in industrial environments.

Can the OP 77A display graphical content or images?

No, the OP 77A is a text-based operator panel with a 4-line alphanumeric display. It does not support graphical or bitmap image display. For graphical HMI functionality, a panel from the SIMATIC TP or MP series would be required.

Troubleshooting

Display remains blank after power on

Check the 24 V DC supply voltage at the panel power connector using a multimeter. Verify the voltage is within the 19.2 V to 28.8 V range. Inspect the supply cable and connector for damage.

Restore the correct supply voltage. If voltage is present 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 shows communication error and cannot connect to PLC

Verify the MPI or PROFIBUS DP address configured on the panel matches the network settings. Check that the bus cable is properly terminated at both ends and that no cable is damaged or disconnected.

Correct any address mismatches in the WinCC flexible project and re-download. Replace damaged cables and ensure proper bus termination resistors are installed at the physical ends of the network segment.

Keypad buttons are unresponsive or intermittently fail

Inspect the membrane keypad for physical damage, contamination, or wear. Test each key systematically in the panel's key test mode if available. Check for any visible damage to the keypad overlay.

Clean the keypad surface with a dry cloth. If individual keys have failed due to wear, the membrane keypad assembly should be replaced. This is a common wear item on operator panels with high usage.

Project download from WinCC flexible fails or times out

Check the PC adapter cable connection between the engineering PC and the panel MPI port. Verify the correct COM port and transfer speed are selected in WinCC flexible transfer settings. Ensure the panel is in transfer mode.

Switch the panel to transfer mode manually via the panel menu. Try a lower baud rate for the transfer. Replace the PC adapter cable if communication cannot be established after verifying all settings.

Alarm messages are not displayed or are displayed incorrectly

Check the alarm configuration in the WinCC flexible project, including the PLC bit addresses assigned to each alarm. Verify that the PLC data area used for alarms is being written correctly by the PLC program.

Correct any incorrect tag or address assignments in the alarm configuration and re-download the project. Confirm the PLC logic is setting and resetting alarm bits as intended using the PLC programming software online monitor.

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