Hirschmann RS20 Basic Switch Installation and Debugging Guide

Hirschmann RS20 Basic Industrial Ethernet Switch Engineering Installation and Debugging Complete Guide

Introduction: Deployment Challenges of Core Nodes in Industrial Networks

In modern industrial automation systems, Ethernet switches have evolved from simple data forwarding devices to critical nodes that determine system availability and security. The Hirschmann RS20 Basic series switches have become the mainstream choice in harsh environments such as automotive manufacturing, rail transportation, and petrochemicals due to their fanless design, redundant power input, wide temperature operating range, and ring redundancy protocol support. However, proper installation and debugging are prerequisites for maximizing its performance. This article will systematically review the hardware installation, electrical connection, grounding specifications, and initial configuration process of RS20 Basic based on official technical documents, helping engineers avoid common misconceptions and ensure the long-term stable operation of network infrastructure.

Chapter 1: Product Overview and Selection Configuration Analysis

1.1 Device Family and Port Combination Logic

The RS20 Basic series offers two basic models: 4-port and 8-port. The product models follow strict coding rules, and engineers need to choose the correct variant based on the actual network topology. The key fields in the model have the following meanings:

Number of ports: RS20-0400... B represents 4 10/100Mbit/s ports; RS20-0800... B represents 8 ports.

Upstream port medium: The 10th to 13th characters define the physical interface of port 1 and port 2. T1 represents twisted pair RJ45 interface, supporting 10/100BASE-T (X); M2 represents Multimode FX, which uses DSC connectors and is suitable for long-distance transmission at 100Mbit/s.

Temperature and voltage range: S in the model represents the standard temperature range (0 ° C to+60 ° C), and D represents the voltage range of 9.6VDC to 60VDC or 18VAC to 30VAC.

Engineering Tip: When selecting fiber port variants, it is important to note that the transmission distance of multimode fiber depends on the fiber mode (usually 2km to 5km), and multimode fiber that complies with the ISO/IEC 793-2 standard (50/125 µ m or 62.5/125 µ m) must be used.

1.2 Mechanical dimensions and installation space requirements

4-port model: The external dimensions are 47mm (width) x 131mm (depth) x 111mm (height), and the weight is approximately 400g.

8-Port Model: Width increased to 74mm, depth and height remain consistent, weight approximately 410g.

Key heat dissipation requirements: The equipment adopts natural convection heat dissipation, and must be installed in a vertical direction, with a minimum gap of 10cm (3.94 inches) between the housing ventilation holes and other objects. If installed in office or living areas, the equipment must be placed in cabinets that comply with EN 60950-1 fire protection requirements.

Chapter 2: Mechanical Installation and Grounding Standards

2.1 DIN rail installation standard process

RS20 Basic adopts a 35mm DIN rail installation method that complies with DIN EN 60175 standard. The specific steps are as follows:

Align the buckle hooks on the upper part of the device with the upper edge of the guide rail.

Press the device as a whole towards the guide rail until the bottom spring lock makes a "click" sound, indicating that it is locked in place.

After installation, pull the equipment firmly to confirm its firmness.

Disassembly method: Use a flathead screwdriver to horizontally insert into the locking groove below the housing, pull vertically downwards to unlock, and at the same time lift the device upwards to detach from the guide rail.

2.2 Strict Implementation of Functional Grounding (FE)

There is an independent grounding screw located at the bottom left of the front panel of the equipment, and a copper wire with a cross-sectional area of at least 1.0mm ² must be used to reliably connect this terminal to the system grounding bar.

Important warning: The shielding layer of shielded twisted pair (STP) has been capacitively coupled to the front panel inside the device, but this connection is only used for high-frequency interference discharge. Functional grounding (FE) is a core measure to protect personnel safety and equipment immunity, and cannot be omitted or replaced with thin wires.

Chapter 3: Electrical Connection between Power Supply and Signal Terminals

3.1 Function definition of 6-pin pluggable terminal block

The device is equipped with a 6-pin terminal block with a locking mechanism, which simultaneously carries the main power supply and fault alarm signals. The pin definitions are as follows (refer to Figure 4 in the manual):

Function Description of Pin Number Symbols

1+24V (P1) redundant power input 1 positive pole (DC) or AC phase line

2 0V power input, 1 return line/AC neutral line

3 FAULT signal contacts (normally closed relay output)

4 FAULT signal contacts (common terminal)

5 0V power input 2 loop/AC neutral line

6+24V (P2) redundant power input 2 positive pole (DC) or AC phase line

3.2 Engineering Practice of Redundant Power Supply

DC power supply: Operating voltage range of 9.6VDC to 60VDC, rated 12VDC to 48VDC. The two inputs (P1 and P2) are internally decoupled through diodes and have no load balancing function. The system automatically selects the input with higher voltage as the main power supply.

AC power supply: Supports 18VAC to 30VAC (50/60Hz), simply connect the AC cable to the+24V (P1) and 0V terminals (P2 is the same).

Key note: If only a single power supply is used, the device will continuously trigger a "power failure" alarm. The solution is to apply the same voltage to both P1 and P2 simultaneously; ② Turn off the power alarm monitoring function through the management software.

3.3 Logic and use of "FAULT" signal contacts

The signal contact is a normally closed circuit relay, which means that the contact is closed in the normal state and disconnected in case of a fault. The triggering conditions include:

Either power supply voltage is below the threshold;

Equipment self-test failed;

Port link interruption (this monitoring function needs to be enabled through the management interface);

The circular redundant network experienced a chain break.

Electrical limitations: Maximum contact switching capability of 1A (SELV circuit), maximum switching voltage of 60VDC or 30VAC. This contact can be used to send a hard wired alarm to the PLC or upper monitoring system.

Chapter 4: Data Interface Connection and Cable Specification

4.1 10/100BASE-T (X) twisted pair port

Connector: Standard RJ45 socket with LED status indicator light.

Auto negotiation and polarity adaptation: Auto negotiation is enabled by factory default, and supports Auto crossover (MDI/MDI-X automatic recognition) and Auto polarity correction.

Cable requirements: It is recommended to use shielded twisted pair (STP) cables that meet Category 5e or higher standards to suppress electromagnetic interference in industrial environments.

4.2 Fiber Port (Multimode DSC)

Connector type: DSC (Duplex SC) interface, requiring the use of 100Base FX standard multimode fiber.

Transmission parameters: Only supports full duplex mode, with a fixed rate of 100Mbit/s.

Cleaning precautions: Fiber end face contamination is the primary cause of optical link failure and must be treated with specialized cleaning tools. It is strictly prohibited to use alcohol swabs to directly wipe the connected jumper end face.

4.3 Serial Management Interface (V.24)

Physical interface: RJ11 socket (6P4C), non electrically isolated.

Connection parameters: data rate 9600bps, data bits 8, stop bit 1, no parity check, no flow control.

Applicable scenario: When network parameters (IP address) are unknown or DHCP service is unavailable, VT100 terminal can be used for local command-line configuration through this interface.

Chapter 5: Status Indication and Startup Self Test

5.1 Power and System Status LEDs

Meaning of LED identification color status

P (Power) green constant light, both power sources are normal

Yellow constantly on, powered by only one power source

Turn off both power sources below the threshold

The FAULT red constant light signal contact is disconnected, indicating an alarm condition

Extinguish the device normally and close the contacts

5.2 Port Status LED (LS/DA)

LS (Link Status, green):

Always on: Link is valid;

Slow flashing (once/cycle): The port is in Standby state (redundant protocol activated);

Flash (3 times/cycle): The port is managed to be closed.

DA (Data Activity, yellow): Blinking indicates that the port is sending and receiving data frames.

Chapter 6 Initial Power On and IP Address Configuration

6.1 Power on process

After completing all wiring and checking for errors, insert the power terminal block. During the device startup process, the port LED will flash sequentially to indicate the boot phase, lasting for about 30 seconds to 1 minute before entering normal operation.

6.2 Four ways to obtain an IP address

HiDiscovery Protocol: A Windows tool provided by Hirschmann that can discover devices without configured IP within the same broadcast domain and manually assign addresses.

DHCP/BOOTP: enabled by default, sends a Discover request when the device starts.

Autoconfiguration Adapter (ACA 11): A hardware adapter connected through the V.24 interface, used for batch deployment of configuration files and IP addresses.

Local V.24 console: Manually set static IP, subnet mask, and gateway through the command line.

Factory default certificate:

User level (read-only): Login=user, Password=public

Management level (read-write): Login=admin, Password=private

Chapter 7 Mandatory Requirements for Installation in Explosion proof Areas

For projects deployed in chemical, oil and gas environments with combustible gases, RS20 Basic holds ATEX 94/9/EC and IECEx certification (certificate number: DEKRA 11ATEX0139 X). The following special conditions must be observed:

Temperature level T4: The ambient temperature range is strictly limited to 0 ° C to+60 ° C (applicable to "B" models).

Shell protection: The equipment must be installed in a cabinet that meets the requirements of EN 60079-15 and has a protection level not lower than IP54.

Transient overvoltage protection: Measures must be taken to prevent the rated voltage from exceeding 40% due to transient interference (such as lightning strikes).

Live operation prohibited: The insertion and removal of connectors (including RJ45, DSC, and V.24 interfaces), as well as the switching of DIP switches, must be carried out in a power-off state.

Chapter 8 Electromagnetic Compatibility Installation Techniques

To achieve the immunity and emission limits specified in EN 61000-6-2 and FCC Part 15 Class A, please note:

The shielding layer of signal lines (especially twisted pair cables) should be looped 360 ° at the cable entrance to ensure a good overlap between the shielding layer and the casing.

The power line and signal line should be wired separately to avoid parallel laying.

For unused optical ports, dust caps should be installed to prevent contamination and avoid reflection of irrelevant optical signals.