Siemens 6AV6355-1AA47-7EC0 OP 77A

€ 885,30

SKU: 6AV6355-1AA47-7EC0 Category: HMI & Display Brand: Siemens

Description
Additional information

The Siemens 6AV6355-1AA47-7EC0 is an operator panel belonging to the SIMATIC HMI OP 77A series, designed for human-machine interface applications in industrial automation environments. This compact panel provides a keypad-based interface for machine monitoring and control, and is part of Siemens' SIMATIC HMI product line. It is intended for use with Siemens SIMATIC PLCs and is configured using the WinCC flexible engineering software.

The OP 77A features a monochrome LCD display and a membrane keypad with function keys, system keys, and numeric entry capability. It supports MPI and PROFIBUS DP communication interfaces for direct connection to SIMATIC S7 PLCs. The panel operates on a 24 V DC supply and is designed for panel-mount installation with a protection rating of IP65 on the front face, making it suitable for use in environments where dust and water ingress are a concern.

The OP 77A is commonly deployed in machine building, manufacturing automation, and process control applications where a cost-effective, robust operator interface is required. It is well suited for tasks such as displaying process values, entering setpoints, acknowledging alarms, and navigating simple control screens. Industries such as packaging, material handling, and general factory automation frequently use this type of panel for local machine-level HMI.

Technical Specifications

Display Type	Monochrome LCD
Display Size	4 lines x 20 characters
Input/Operating Voltage	24 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)
Mounting	Panel mount
Certifications	CE, UL
Engineering Software	WinCC flexible
Series/Product Family	SIMATIC HMI OP 77A

Common Error Codes & System Events

Event ID: 10000: Communication error between the HMI panel and the connected PLC. The connection to the configured controller cannot be established.
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 HMI panel has lost communication with the controller.
Inspect the communication cable for damage or loose connectors. Check bus termination and cable shielding. Restart the HMI panel and PLC if the connection is not restored automatically.
Event ID: 40000: Project download error. The project transfer from the engineering PC to the HMI panel has failed.
Verify the transfer cable and PC interface settings. Ensure the HMI panel is in transfer mode before initiating the download. Check that the WinCC flexible project is compatible with the OP 77A device type.
Event ID: 20000: Tag read error. A configured tag could not be read from the PLC.
Verify that the tag address in the HMI project matches the actual PLC data block or memory address. Check PLC program to confirm the address is valid and accessible.
Event ID: 20001: Tag write error. A value could not be written to the configured PLC tag.
Check that the target PLC address is not write-protected. Verify the data type of the tag in the HMI project matches the PLC variable definition.
Event ID: 50000: System memory low. The HMI panel is running low on available runtime memory.
Reduce the number of active screens or configured tags. Simplify the project structure and re-download the project to the panel.
Event ID: 60000: Operating system error. An internal system fault has been detected on the HMI panel.
Perform a power cycle on the panel. If the error persists, perform a factory reset and re-download the project. Contact Siemens technical support if the fault recurs.

Frequently Asked Questions

Which PLCs are compatible with the OP 77A?

The OP 77A is designed for use with Siemens SIMATIC S7-200, S7-300, and S7-400 PLCs via MPI or PROFIBUS DP interfaces. It can also connect to S7-200 via PPI protocol.

What software is used to configure the OP 77A?

The OP 77A is configured using Siemens WinCC flexible engineering software. The project is then transferred to the panel via a PC adapter cable or through the MPI/PROFIBUS network.

What is the supply voltage for the 6AV6355-1AA47-7EC0?

The panel requires a 24 V DC supply voltage for operation.

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.

Can the OP 77A display graphics or images?

No, the OP 77A uses a character-based monochrome LCD display and does not support graphical images. It is limited to text-based screens with function key navigation.

Troubleshooting

Display remains blank after power on

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

Restore the correct 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.

HMI panel shows 'No connection to PLC' message

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

Replace or reseat the communication cable. Confirm the PLC station address and baud rate settings in the HMI project match the physical PLC configuration. Ensure the PLC is powered and in RUN mode.

Project transfer from PC to panel fails

Confirm the panel is set to transfer mode by pressing the appropriate key combination during startup. Check the PC adapter cable type and the COM port or USB settings in WinCC flexible.

Set the panel to transfer mode before initiating the download. Select the correct interface and baud rate in WinCC flexible transfer settings. Try a different PC adapter cable if the issue persists.

Function keys do not respond when pressed

Inspect the membrane keypad for physical damage, contamination, or deformation. Check the HMI project to confirm that functions are correctly assigned to the keys.

Clean the keypad surface with a dry cloth. If keys are physically damaged or unresponsive after cleaning, the keypad membrane may need replacement. Verify key assignments in the WinCC flexible project and re-download if necessary.

Alarm messages are not displayed on the panel

Check that alarm tags are correctly configured in the WinCC flexible project and that the corresponding PLC bit addresses are active. Verify the alarm view screen is included in the project navigation.

Review the alarm configuration in WinCC flexible and confirm that the PLC addresses used for alarm triggers are correct. Re-download the project to the panel and test alarm activation from the PLC side.

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