Siemens 6ES5490-7LC11 Expansion Module

This expansion module increases I/O capacity for Siemens SIMATIC S5 automation systems. It connects to the main rack via a dedicated expansion cable. Therefore, it enables distributed I/O placement for large control applications.

Physical and Connection Specifications

The Siemens 6ES5490-7LC11 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 module to the S5 expansion backplane. Additionally, the unit includes an expansion interface for linking additional racks.

Parameter	Specification
Brand	Siemens
Full Model	6ES5490-7LC11
Category	Expansion Module
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)
Expansion Interface	1 x 48-pin Female Connector (To Next Rack)
Expansion Cable	6ES5490-8MB11 (Available Separately)
Maximum Cable Length	10 meters (32.8 feet) Between Racks
Maximum Expansion Racks	4 Additional Racks per System
Maximum Total I/O	2048 Digital Points or 512 Analog Channels
Signal Pass-Through	Data Bus + Address Bus + Power Lines
On-Board Components	1 Passive Backplane PCB + 2 Edge Connectors + 4 Bus Terminating Resistors
Energy Storage	None (Passive Module)
Operating Voltage	5 VDC from Backplane (0.1 A Typical)
Power Consumption	0.5 W (Typical)
Operating Temperature	0°C to +55°C (32°F to 131°F)
Storage Temperature	-25°C to +85°C (-13°F to 185°F)
Mounting Type	S5 Rack (Single Slot)
Status Indicators	1 Green LED (Power) + 1 Green LED (Expansion Active)

Expansion Capabilities and System Growth

The Siemens 6ES5490-7LC11 allows up to four additional racks per S5 system. Specifically, each expansion module connects one rack to the next in a chain configuration. In addition, the maximum cable length of 10 meters enables flexible cabinet layouts. Moreover, the total system supports 2048 digital I/O points or 512 analog channels. Consequently, you can build large control systems without centralizing all I/O.

Signal Pass-Through and Bus Architecture

This expansion module passes data, address, and power signals between racks. For instance, the backplane interface receives signals from the main rack or previous expansion. In addition, the expansion interface forwards these signals to the next rack. Furthermore, bus terminating resistors prevent signal reflection at the last module. Thus, the Siemens 6ES5490-7LC11 maintains signal integrity across long cable runs.

Passive Design and Maintenance Advantages

This expansion module uses a passive PCB without active electronic components. Specifically, it contains no processors, memory chips, or configurable logic. In addition, the passive design generates no heat and consumes very little power. Moreover, there are no software drivers or firmware updates required. Therefore, this module requires no periodic maintenance or configuration.

Installation and Diagnostic Indicators

Two 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 Expansion Active LED illuminates when the link to the next rack functions correctly. Additionally, the module occupies one slot in the S5 rack. Thus, you can diagnose expansion link status instantly without external tools.