Siemens 6ES5523-3UA11 Communications Processor

This communications processor handles data exchange for Siemens SIMATIC S5 automation systems. It manages serial communication between the PLC and external field devices. Therefore, it enables connectivity with drives, HMIs, and host computers.

Physical and Processor Specifications

The Siemens 6ES5523-3UA11 measures 25.0 cm in length and 18.0 cm in width. Moreover, its module weight equals approximately 0.88 kg for rack mounting. A single 48-pin male connector links this processor to the S5 backplane. Additionally, the unit includes two independent serial communication ports.

Parameter	Specification
Brand	Siemens
Full Model	6ES5523-3UA11
Category	Communications Processor
Dimensions (L x W x H)	25.0 cm x 18.0 cm x 5.5 cm (9.84″ x 7.09″ x 2.17″)
Module Weight	0.88 kg (1.94 lbs)
Backplane Interface	1 x 48-pin Male Connector (S5 Rack)
Power Supply Input	5 VDC from Backplane (0.9 A Typical)
Power Consumption	4.5 W (Typical)
Processor Type	8-bit Microcontroller (10 MHz)
Program Memory	32 kB ROM (Firmware)
User Memory	16 kB RAM (Battery Backed)
Backup Battery	6ES5980-0UA11 (Lithium, 5 Year Life)
Communication Ports	2 x 9-pin D-Sub Male (RS-232C/RS-422 Selectable)
Supported Protocols	ASCII + RK512 + 3964R + SINEC L1
Baud Rate Range	300 to 38400 baud
Data Bits	7 or 8 Bits (Configurable)
Parity Options	None, Even, Odd
Stop Bits	1 or 2 Bits
RS-422 Cable Length	500 meters (1640 feet) Maximum
RS-232 Cable Length	15 meters (49 feet) Maximum
On-Board Components	1 Microcontroller + 2 UARTs + 3 Memory Chips + 2 Line Drivers + 2 Optocouplers + 6 Protection Diodes + 1 Voltage Regulator + 2 Isolation Transformers
Energy Storage	3 x 100 µF Electrolytic Capacitors (35V) + 2 x 10 µF Tantalum (25V) + 1 x CR2032 Backup Battery
Battery Backup Time	5 Years (Typical for RAM Retention)
Operating Temperature	0°C to +55°C (32°F to 131°F)
Mounting Type	S5 Rack (Single Slot)
Status Indicators	1 Green LED (Power) + 1 Green LED (Run) + 2 Yellow LEDs (Port Activity) + 1 Red LED (Fault)

Communication Protocols and Network Connectivity

The Siemens 6ES5523-3UA11 supports multiple industrial communication protocols. Specifically, the RK512 protocol enables peer-to-peer communication with other Siemens devices. In addition, the ASCII protocol allows connection to barcode scanners and printers directly. Furthermore, the 3964R protocol provides reliable data transfer with comprehensive error checking. Moreover, SINEC L1 connects this processor to Siemens L1 fieldbus networks. Consequently, this module connects S5 PLCs to a wide range of external devices.

RS-232 and RS-422 Interface Flexibility

This communications processor features switch-selectable RS-232 or RS-422 interfaces per port. For instance, RS-232 suits short-distance connections up to 15 meters. In addition, RS-422 allows cable runs up to 500 meters for remote installations. Furthermore, each 9-pin D-sub connector accommodates both wiring schemes. Thus, you can configure each port independently for point-to-point or multi-drop networks.

Energy Storage and Data Retention

This communications processor stores energy using five onboard capacitors for power filtering. Specifically, three electrolytic capacitors smooth the 5 VDC supply for stable processor operation. In addition, two tantalum capacitors provide high-frequency noise suppression for UART circuits. Furthermore, a replaceable lithium battery retains data memory and configuration settings. Therefore, the Siemens 6ES5523-3UA11 preserves communication parameters for up to five years.

Installation and Diagnostic Indicators

Five LED indicators provide operational status at a glance on this module. First, a green Power LED lights when the 5 VDC backplane supply is present. Second, a green Run LED flashes during normal firmware execution. Third, two yellow Port Activity LEDs illuminate during data transmission or reception. Finally, a red Fault LED indicates hardware errors or watchdog timeouts. Thus, you can diagnose communication status instantly without external tools.