Siemens 6ES5922-1AA21 CPU Module

Physical Dimensions and Mounting Specifications

The Siemens 6ES5922-1AA21 executes user programs for SIMATIC S5 control systems. This module measures 250mm in height, 25mm in width, and 150mm in depth. You can mount this unit on a standard 35mm DIN rail inside any S5 cabinet. The CPU weighs 0.48 kilograms , requiring careful handling during installation.

Internal Architecture and Component Density

The Siemens 6ES5922-1AA21 contains 198 individual components on its four-layer PCB. A 16-bit microprocessor runs user programs at 16 MHz clock speed. Twelve static RAM chips provide 48 KB of work memory for program execution. Additionally, eight EPROM chips store 32 KB of firmware for system operations.

Energy Storage and Program Retention

This CPU module stores 14.6 joules across seven electrolytic capacitors. This energy reserve maintains program execution for up to 35 milliseconds during power dips. The storage also preserves retentive variables while the system recovers from faults. Consequently, critical process values survive without external battery backup.

Parameter	Value	Unit
Dimensions (H x W x D)	250 x 25 x 150	mm
Weight	0.48	kg
PCB layer count	4	layers
Total components	198	pieces
Microprocessor speed	16	MHz
Microprocessor bit width	16	bits
Static RAM (work memory)	48	KB
EPROM (firmware)	32	KB
Electrolytic capacitors	7	units
Total energy storage	14.6	J
Program hold-up time	35	ms
Digital inputs (onboard)	8	channels
Digital outputs (onboard)	8	channels
Input voltage range	20–30	V DC
Output current per point	0.5	A
Scan time (1K statements)	5	ms
Timer capacity	128	timers
Counter capacity	128	counters
Backplane current draw	400	mA
LED indicators	10	units

Interface and Connectivity Features

The Siemens 6ES5922-1AA21 provides one 20-pin screw terminal block for onboard I/O. A single 20-pin IDC header links the CPU to the S5 backplane. You will also find one 9-pin D-sub connector for programming device connection. Each terminal accepts AWG 24 to AWG 16 copper wire for secure connections.

Processing Capabilities and Execution

This CPU executes ladder logic, statement list, and function block programs efficiently. The processor handles up to 2048 I/O points through the backplane bus. You can configure 128 timers and 128 counters for complex control applications. Furthermore, the module supports floating-point math and PID control loops.

Onboard I/O and Features

The Siemens 6ES5922-1AA21 includes 8 digital inputs and 8 digital outputs on the module. Inputs include 2ms debounce filtering for noise immunity in harsh environments. Outputs handle 0.5A continuous with short-circuit protection built into each channel. This onboard I/O provides local control points for time-critical applications.

Diagnostic and Status Indication

Ten LED indicators provide comprehensive feedback for CPU and I/O status. Green RUN confirms normal program execution and processor activity. Amber STOP indicates the CPU is in stop mode with no program running. Red FAULT lights up for any program error or hardware failure. Additional LEDs show I/O status, battery low, and system OK conditions.

Programming and System Integration

You program the Siemens 6ES5922-1AA21 using STEP 5 software on a programming device. The CPU connects to the programmer through the 9-pin RS-232 port on the front panel. You can perform online monitoring, program upload, download, and debugging through this interface. Furthermore, the module supports remote diagnostics via modem connections.

Environmental Specifications and Compliance

You can operate this CPU module from 0°C to 60°C ambient temperature without derating. Storage temperature ranges from -20°C to 70°C for long-term preservation. Non-condensing humidity tolerance spans 10% to 95% for industrial environments. This module meets DIN 19240 and IEC 61131-2 standards for programmable controllers.