Siemens C79451-A3437-B122 Operator Panel

Technical Specifications and Panel Design

This operator panel provides a compact HMI for Siemens industrial control systems. The Siemens C79451-A3437-B122 allows machine operators to monitor processes and enter commands efficiently. You can mount this unit onto a control cabinet door or operator console. Its rugged front face withstands industrial dust and liquid splashes. The panel weighs approximately 1.0 kilogram. Its dimensions measure 14 cm in height, 20 cm in width, and 5.5 cm in depth.

Parameter	Specification
Brand	Siemens
Model	C79451-A3437-B122
Category	Operator Panel / HMI Terminal
Weight	1.0 kg
Height	14 cm
Width	20 cm
Depth	5.5 cm
Display Type	Monochrome LCD (STN)
Display Resolution	240 x 64 pixels (graphic) / 8 x 40 characters (text)
Active Display Area	10.5 cm x 4.8 cm
Backlight Type	LED (green)
Number of Keys	18 membrane keys
Function Keys	8 programmable soft keys
Communication Ports	RS-232, RS-422, RS-485
Communication Speed	300 to 19.2 Kbps
Input Voltage	24V DC (±20%)
Power Consumption	8 Watts maximum
Front Panel Rating	IP65 (NEMA 4)
Energy Storage	None (no internal battery)
Component Count	LCD panel, LED backlight, membrane keypad, controller PCB

Display Features and Visual Indicators

The monochrome LCD presents text and basic graphics with high contrast. An LED backlight provides uniform green illumination for low-light environments. The Siemens C79451-A3437-B122 displays up to 8 lines of 40 characters each. You can create custom screens for machine start-up and shutdown sequences. The display contrast adjusts through a software setting in the configuration. A green LED indicates proper power and communication status with the PLC. The screen updates within 100 milliseconds of receiving new data.

Keypad Layout and Operator Controls

Eighteen membrane keys provide full operator control functionality for the machine. The keypad includes dedicated numeric keys for rapid data entry tasks. The Siemens C79451-A3437-B122 features eight soft keys for programmable functions. Each soft key accepts custom labeling for application-specific operations. Every key delivers tactile click feedback for confident operator input. The spill-resistant design protects against accidental liquid splashes on the panel. Key presses register within 50 milliseconds of activation.

Communication and System Integration

You connect this panel to a Siemens PLC through any available serial port. The unit supports RS-232, RS-422, and RS-485 physical interface standards. A 9-pin D-sub connector provides the primary programming and runtime connection. The Siemens C79451-A3437-B122 draws operating power from an external 24V DC supply. It requires no internal battery for configuration or application data retention. Therefore, all screen settings reside in the host controller memory. The panel acts purely as a display and input device.

Installation and Environmental Guidelines

You must cut a mounting hole measuring 135 mm by 190 mm in the cabinet door. The panel seals against the door with an included rubber gasket. The front face carries an IP65 rating for dust and water protection. Consequently, you can clean the panel with a damp cloth safely. The operating temperature ranges from 0°C to 50°C for reliable performance. You should avoid exposing the panel to direct sunlight for extended periods. The LED backlight has an average lifespan of 100,000 operating hours.