Siemens 6AV6355-1AA47-7DM2 OP 77A

€ 2.070,40

SKU: 6AV6355-1AA47-7DM2 Category: HMI & Display Brand: Siemens

Description
Additional information

The Siemens 6AV6355-1AA47-7DM2 is an operator panel belonging to the SIMATIC HMI OP 77A series, manufactured by Siemens. It is a compact, key-operated panel designed for machine-level human-machine interface applications, providing operators with a straightforward means of monitoring and controlling industrial processes. This unit is part of the SIMATIC HMI Basic Panels generation, intended for use with Siemens SIMATIC S7 and other compatible controller families.

The OP 77A features a monochrome LCD display and a membrane keypad with function keys, system keys, and numeric entry keys, enabling reliable operator input without a touchscreen. It supports the MPI and PROFIBUS DP communication interfaces for direct connection to SIMATIC S7-200, S7-300, and S7-400 PLCs. The panel is configured using WinCC flexible software and offers recipe management, alarm logging, and trend display capabilities within its onboard memory. The unit is built to industrial standards with a protection rating suitable for panel-front mounting in control cabinets.

The OP 77A is widely deployed in manufacturing, packaging, and process automation environments where a cost-effective, robust operator interface is required at the machine level. Its compact form factor makes it suitable for integration into control panels with limited space, and its keypad-based operation is preferred in environments where touchscreen reliability may be a concern. Industries such as automotive, food and beverage, and general machine building commonly use this panel for local operator control stations.

Technical Specifications

Display Type	Monochrome LCD
Display Size	4 inches
Input/Operating Voltage	24 V DC
Power Consumption	Max. 6 W
Communication Interface	MPI, PROFIBUS DP
Operating Temperature	0 °C to +50 °C
Storage Temperature	-20 °C to +60 °C
Relative Humidity	10% to 90%, non-condensing
IP Rating (Front)	IP65
IP Rating (Rear)	IP20
Mounting	Panel mounting
Certifications	CE, UL
Configuration Software	WinCC flexible 2005 or higher
Series/Product Family	SIMATIC HMI OP 77A

Common Error Codes and System Events

Event ID: 010000: System startup completed successfully. The HMI device has booted and is ready for operation.
No action required. This is an informational system event logged at startup.
Event ID: 040000: Communication error detected on the MPI or PROFIBUS DP interface. The panel cannot establish or maintain a connection to the configured PLC.
Check MPI/PROFIBUS cable connections and termination resistors. Verify the PLC address and baud rate settings match the HMI project configuration. Ensure the PLC is powered and in RUN mode.
Event ID: 070000: Tag read error. The HMI panel is unable to read a configured process tag from the connected controller.
Verify the tag address in the WinCC flexible project is correct and that the corresponding data block or memory area exists in the PLC program. Check communication link integrity.
Event ID: 080000: Tag write error. A write operation to a PLC tag has failed.
Check that the target PLC memory address is not write-protected and that the address exists. Verify communication is active and the PLC is in a state that accepts write commands.
Event ID: 110000: Recipe data error. A recipe transfer to or from the PLC has failed or the recipe data is inconsistent.
Check recipe configuration in WinCC flexible for correct tag assignments and data types. Re-transfer the project to the HMI panel and retry the recipe operation.
Event ID: 140000: Project download error or project data corrupted on the HMI device.
Re-download the WinCC flexible project to the OP 77A using the correct transfer settings. Ensure the PC and HMI are connected via MPI or serial transfer cable and that transfer mode is active on the panel.
Event ID: 060000: Alarm buffer overflow. The number of pending or logged alarms has exceeded the available buffer capacity.
Acknowledge and clear existing alarms on the panel. Review the alarm configuration in WinCC flexible to reduce unnecessary alarm triggers or increase acknowledgment frequency in the process.

Frequently Asked Questions

Which PLCs are compatible with the OP 77A (6AV6355-1AA47-7DM2)?

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 the PPI protocol depending on configuration.

What software is required to configure the OP 77A?

The OP 77A is configured using Siemens WinCC flexible 2005 or a later compatible version. Projects are downloaded to the panel via an MPI connection or a serial PC/PPI cable.

What is the supply voltage for the 6AV6355-1AA47-7DM2?

The panel operates on a 24 V DC supply voltage. Ensure the power supply is within the specified tolerance range to avoid damage or instability.

Does the OP 77A support touchscreen input?

No, the OP 77A uses a membrane keypad for operator input and does not feature a touchscreen. Input is performed via function keys, system keys, and a numeric keypad.

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

The front panel of the OP 77A carries an IP65 protection rating, making it suitable for panel-front mounting in environments where dust and water jets may be present.

Troubleshooting

Display remains blank after power is applied

Check the 24 V DC supply voltage at the power connector on the rear of the panel using a multimeter. Verify polarity is correct and voltage is within specification.

If supply voltage is correct and the display remains blank, the internal power supply or backlight may have failed. The unit should be inspected for internal fuse continuity and, if necessary, sent for repair or replacement of the display assembly.

HMI panel shows 'No connection to PLC' or communication error on screen

Verify the MPI or PROFIBUS DP cable is securely connected at both the panel and PLC ends. Check bus termination resistors are correctly placed at both ends of the network segment. Confirm the PLC address and baud rate in the WinCC flexible project match the actual PLC settings.

Correct any address or baud rate mismatches in the project and re-download to the panel. Replace damaged cables or connectors. Ensure only one active bus termination is present at each end of the segment.

Panel cannot enter transfer mode for project download

The panel must be manually set to transfer mode before a project can be downloaded from WinCC flexible. Check whether the panel is currently running a project that prevents automatic transfer mode activation.

Restart the panel and interrupt the boot sequence to access the loader menu, then select 'Transfer'. Alternatively, configure the project to allow transfer mode activation via a function key or from the control panel settings.

Function keys do not respond or produce incorrect actions

Check the WinCC flexible project configuration to verify that function key assignments are correctly defined for the active screen. Confirm the project version downloaded to the panel matches the intended configuration.

Re-download the correct project version to the panel. If keys are physically unresponsive, inspect the membrane keypad for damage or contamination and replace the keypad assembly if necessary.

Alarm messages are displayed in incorrect language or with garbled text

The language settings in the WinCC flexible project may not match the language configured on the HMI panel, or the text list entries may contain unsupported characters for the panel's character set.

Verify the active language setting on the panel matches a language included in the downloaded project. Review text entries in WinCC flexible for unsupported special characters and re-download the corrected project.

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