
Chapter 3 Installation and Grounding Standards
3.1 DIN rail installation
Hang the upper hook of the device onto the 35mm guide rail and press down until the lock buckle clicks into place.
When disassembling, insert a screwdriver horizontally into the bottom locking groove, pull down and flip up the device.
3.2 Functional Grounding
All models are equipped with independent grounding screws (as shown in Figure 12 of the manual), which must be connected to the system grounding bar using copper wires not smaller than the power wire diameter. Important: The grounding screw must be connected first and disconnected last, and the grounding wire diameter must be at least the same as the power supply wire (as required in the control diagram on page 14 of the manual).
3.3 Ferrite Accessories (Specific Models)
For 8-12 port models and DNV GL certified equipment, the accompanying ferrite should be placed on the power cord (near the input side of the equipment, at a distance of ≤ 5cm) and wound twice to suppress high-frequency interference and ensure EMC compliance. The characteristic P (PoE) model does not require ferrite.
Chapter 4 SFP Module Selection and Temperature Derating Rules
The BRS series supports Fast Ethernet, Gigabit Ethernet, 2.5 Gigabit, and bidirectional SFP transceivers, but requires the use of Hirschmann authentication modules (see Chapter 9 of the manual). Different modules have a derating effect on the operating temperature of the equipment, which must be accounted for during project design.
4.1 Reduction principle
For standard temperature (+60 ° C) equipment, if a module without the "EEC" suffix is used, the overall allowable ambient temperature of the equipment will be reduced by 15K (for example, if M-SFP-LX/LC has no EEC, the maximum operating temperature of the equipment will be reduced to 45 ° C).
Extended temperature (+70 ° C) devices typically require the use of modules with "EEC", otherwise the reduction is equally significant (see manual tables 35-39).
Some high-speed modules (such as M-SFP-2.5-LH/LC) may result in a 2K derating even when used in+70 ° C equipment (Table 37).
Selection suggestion: Priority should be given to wide temperature modules with the suffix "EEC" to ensure full performance of the equipment at extreme temperatures.
4.2 Fiber optic transmission distance
Tables 29 to 34 in the manual provide detailed information on the wavelength, fiber type, system attenuation, and corresponding maximum transmission distance (including 3dB system margin) for each module. For example:
Multi mode SFP (MM, 50/125 µ m, 1310nm): 0-5km.
Single mode (SM, 1310nm): 0-25km (standard), 25-65km (SM+), 47-104km (LH, 1550nm).
2.5G module: OM3 multi-mode can reach 550m, single-mode can reach 20km or 45km (SM+).
Mixing is strictly prohibited: LH only applies to LH, SM applies to SM, and MM applies to MM, otherwise the link will fail or the transceiver will be damaged.
Chapter 5 Display Elements and State Diagnosis
5.1 System LEDs (Power, Status, ACA, PoE)
Power (yellow/green): yellow=single power supply, green=dual normal, off=no power; Green flashing 4 times/second indicates that software update is in progress.
Status (green/red): Green=Device ready; Red=not ready; Red green alternating flashing=recovery mode.
ACA (green/yellow): Indicates the status of the USB-C configuration adapter (green=connected, yellow=not ready, flashing 3 times=read/write operation).
PoE (green/yellow): Green=PoE voltage is normal, yellow=power supply voltage is too low to support PoE.
5.2 Port LED (LS/DA)
LS (green): Always on=link valid; Slow flashing=port in Standby; Flash (3 times/cycle)=Port is managed to be closed or automatically disabled (due to error detection).
DA (yellow): flashing=data transmission and reception; Flash=The port is automatically disabled due to abnormal detection.
Start self check: After about 60 seconds of power on, each LED will light up in sequence. Wait for the Status green light to remain on, indicating that the system is operational.

Chapter 6: Digital Input and USB-C Management Interface
6.1 Digital Input (2-pin Terminal)
Used to connect digital sensors (such as door switches, temperature alarms), capture external signals, and trigger device actions.
Electrical parameters: Input voltage range -32~+32V DC, nominal+24V, high level (state "1") ≥+11V, low level (state "0") ≤+5V, maximum input current 15mA (see Table 22 in the manual).
Only some wide shell models have this interface (as indicated in Table 12).
6.2 USB-C interface (ACA22-USB-C)
Supports USB 2.0 master/slave mode, used to connect AutoConfiguration Adapter (ACA22) for configuration backup/restore and software upgrade.
Usage restrictions in explosion-proof areas: In hazardous environments, only ACA22-USB-C (EEC) with mechanical locking can be used, and insertion and removal must be carried out in a power-off state (emphasized in multiple places on pages 13-18 of the manual).
USB cable is only for configuration and cannot be connected for a long time (except in non explosion proof areas).
Chapter 7 Compliance Operation of Explosion proof Zone (Class I Division 2/ATEX)