Siemens 6AV6355-1AA47-7HC2 OP 77A

€ 2.495,00

SKU: 6AV6355-1AA47-7HC2 Category: HMI & Display Brand: Siemens

Description
Additional information

The Siemens 6AV6355-1AA47-7HC2 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, keypad-operated interface for machine monitoring and control. It is intended for use with Siemens SIMATIC S7 and other compatible controller families.

The OP 77A features a monochrome LCD display with a resolution of 128 x 64 pixels, providing clear visualization of process values, alarms, and status messages. The panel is operated via a membrane keypad with function keys, system keys, and numeric input keys, making it suitable for environments where touchscreen operation is not required. It supports MPI and PROFIBUS DP communication interfaces for direct connection to SIMATIC S7-200, S7-300, and S7-400 PLCs, and is configured using WinCC flexible software. The unit operates on a 24 V DC supply and is rated IP65 at the front panel for protection against dust and water ingress.

The OP 77A is widely used in machine building, manufacturing automation, and process control applications where a cost-effective, robust operator interface is required. Its compact form factor and keypad-based operation make it suitable for installation in control cabinets and machine panels with limited space. Industries such as automotive, food and beverage, packaging, and general manufacturing commonly deploy this panel for local operator interaction with PLCs and control systems.

Technical Specifications

Display Type	Monochrome LCD
Display Resolution	128 x 64 pixels
Operating Voltage	24 V DC
Voltage Tolerance	19.2 V DC to 28.8 V DC
Power Consumption	Max. 4.5 W
Communication Interface	MPI, PROFIBUS DP
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)
Configuration Software	WinCC flexible 2005 or higher
Mounting	Panel mounting
Certifications	CE, UL, cULus

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 configuration in WinCC flexible. Ensure the PLC is powered and in RUN mode.
Event ID: 10001: Configured connection to the PLC is not available or has been interrupted during operation.
Inspect the communication cable for damage. Verify bus termination and cable shielding. Check that the PLC address and baud rate match the project configuration.
Event ID: 20000: Project download error. The configuration project could not be transferred to the panel successfully.
Verify the PC-to-panel connection (MPI or serial). Ensure WinCC flexible version compatibility. Retry the download and check for sufficient panel memory.
Event ID: 40000: System memory low or memory overflow on the HMI panel.
Reduce the number of active alarms or data records stored on the device. Review the project for unnecessary data logs or alarm buffers and optimize memory usage.
Event ID: 50000: Internal device error or hardware fault detected on the panel.
Perform a panel restart. If the fault persists, perform a factory reset via the panel's loader menu. If the issue continues, the unit may require repair or replacement.
Event ID: 60000: Alarm buffer overflow. The number of pending alarms has exceeded the configured buffer capacity.
Acknowledge and clear existing alarms on the panel. Review the alarm configuration in WinCC flexible and increase the alarm buffer size if required.
Event ID: 70000: Configuration error detected. The loaded project contains settings incompatible with the panel hardware or firmware version.
Verify that the WinCC flexible project is configured for the correct panel type (OP 77A). Update the panel firmware if necessary and re-download the project.

Frequently Asked Questions

Which PLCs are compatible with the OP 77A (6AV6355-1AA47-7HC2)?

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 PPI protocol depending on configuration.

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 an MPI connection or a serial PC adapter.

What is the supply voltage for the 6AV6355-1AA47-7HC2?

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

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

The front panel of the OP 77A is rated IP65, providing protection against dust ingress and low-pressure water jets. The rear of the unit is rated IP20.

Can the OP 77A display graphics or only text?

The OP 77A features a monochrome 128 x 64 pixel LCD display capable of showing both text and simple bitmap graphics, including bar graphs and status symbols as configured in WinCC flexible.

Troubleshooting

Display remains blank after power is applied

Measure the 24 V DC supply voltage at the panel's power connector. Verify the voltage is within the 19.2 V DC to 28.8 V DC range. Check the power supply cable and connector for damage or loose connections.

Correct the supply voltage if out of range. Replace the power cable or connector if damaged. If the supply is correct and the display remains blank, the internal power supply or display unit may be faulty and the panel should be sent for repair.

Panel fails to communicate with the PLC

Check the MPI or PROFIBUS DP cable connections at both the panel and PLC ends. Verify bus termination resistors are correctly placed at both ends of the bus. Confirm that the PLC station address and baud rate in the WinCC flexible project match the PLC configuration.

Replace or reseat the communication cable. Correct the bus termination. Update the WinCC flexible project with the correct PLC address and baud rate, then re-download the project to the panel.

Project download from PC to panel fails or times out

Verify the PC-to-panel connection using an MPI adapter or PC adapter cable. Ensure the correct COM port and transfer settings are selected in WinCC flexible. Check that the panel is in transfer mode (accessible via the loader menu on startup).

Switch the panel to transfer mode by holding the appropriate key during startup to access the loader. Select the correct interface and baud rate in WinCC flexible and retry the download. Replace the adapter cable if the connection is intermittent.

Keypad buttons are unresponsive or register incorrect inputs

Inspect the membrane keypad surface for physical damage, contamination, or wear. Test each key individually in the panel's diagnostic or startup menu if available.

Clean the keypad surface with a dry cloth. If keys are physically damaged or worn, the membrane keypad assembly should be replaced. This typically requires panel disassembly and sourcing a compatible replacement keypad membrane.

Panel repeatedly displays alarm buffer overflow messages

Review the active and pending alarms on the panel display. Check the WinCC flexible project for the configured alarm buffer size and the number of alarm events being generated by the connected PLC.

Acknowledge and clear all active alarms on the panel. In WinCC flexible, increase the alarm buffer size and re-download the project. Investigate the root cause of repeated alarms in the PLC program to reduce alarm frequency.

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