External fuse: The positive pole (or phase line) needs to be connected to an external slow melting fuse, and the rated value is selected according to the voltage (page 64 of the manual).
3.2 PoE model (RS232/RS32) power supply architecture
RS22/RS32 itself does not directly accept wide voltage input, but provides 48V DC (adjustable to 54V) to the device through an external PoE power supply unit (RPS90/48V LV or RPS90/48V HV), while the last four ports are powered by the internal PoE circuit of the device.
RPS90/48V LV (low voltage type): Input 24-48V DC, output 48-54V DC/90W (below 60 ° C), suitable for vehicle or battery powered scenarios.
RPS90/48V HV (high voltage type): Input 90~265V AC or 48~320V DC, with the same output, suitable for direct connection to mains power or high voltage DC bus.
Wiring precautions:
LV type: 2-pin input terminal (+/-), wire length ≤ 2m.
HV type: 3-pin input terminals (protective ground, -,+). If the input DC>125V, an external fuse (Table 14 in the manual) is required, and the AC input needs to be grounded.
PoE output: RS232/RS32 receives PoE voltage through a 6-pin terminal (shared with the signal contact), with pin 1/4 being+and pin 2/3 being - (Table 15 in the manual). The length of the power supply line between the device and the PoE power supply must be less than 0.5m.
Ferrite accessories: For RS22 models with 16 ports and above (RS22-16/17/24/25), the accompanying ferrite magnetic ring needs to be wrapped around the PoE input cable (twice, near the device end) to meet EMC conduction emission requirements.
Chapter 4: DIP Switches and HIPER Ring Redundancy Configuration
The front panel of RS20/RS30/RS485/RS22/RS32 is equipped with a 2-pin DIP switch (Figure 19 in the manual), which is used to enable the ring network redundancy function at the hardware level to avoid software configuration errors causing ring network failure.
Switch 1 (RM): ON=Enable Redundancy Manager (this device acts as a ring network manager).
Switch 2 (Stand by): ON=Enable Stand by coupling function (for backup links between redundant ring networks).
Combinatorial Logic (Manual Table 6):
RM=OFF, Stand by=OFF: Ring network redundancy is turned off (normal mode).
RM=ON, Stand by=OFF: Enable the ring network manager, and the ring network ports are ports 1 and 2 of module 1.
RM=OFF, Stand by=ON: Enable the coupling manager, with port 3 as the control port and port 4 as the coupling port (used to connect two ring networks).
RM=ON, Stand by=ON: Force software configuration (DIP switch settings are overridden).
Factory default: Both switches are ON (i.e. software configuration takes priority), so if software configuration is not performed during the initial power on, the ring network function is actually not enabled. Engineers need to clarify the RM role based on the actual topology before powering on or through software settings.
Chapter 5 Port and SFP Selection
5.1 Port Type Overview
100Mbps twisted pair (RJ45): Supports 10/100BASE-TX, Auto negotiation, Auto crossover, Auto polarization, up to 100m in length.
100Mbps fiber optic (DSC/ST): multimode (M2/M4) or single-mode (S2/S4/E2/L2/G2), supports full/half duplex, default full duplex. The transmission distance is shown in Table 19 of the manual (the maximum distance for multimode is 5km, the maximum distance for single-mode is 30km, and the long distance can reach 176km).
Gigabit SFP slot (O6): used for RS30/RS32/RS40, supporting 100/1000M SFP modules (Hirschmann certified module required).
Gigabit twisted pair (RJ45): 10/100/1000BASE-T, Auto negotiation, up to 100m in length.
Combo port (CC, RS40 only): Each Combo port provides both SFP slots and RJ45 sockets, but they are mutually exclusive (RJ45 disabled when SFP is inserted).
SFP usage restrictions:
For the 4 upstream port models of RS30/RS32 (such as RS30-0802OOZZ), the top two SFP slots (OO) support gigabit or 100Mbps SFP, while the bottom two slots (ZZ) only support 100Mbps SFP.
When the ambient temperature is>60 ° C or<0 ° C, a wide temperature SFP module with the suffix "EEC" must be used (page 67 of the manual).
5.2 Fiber Optic Connection Rules
Absolute prohibition of mixing: LH (long-distance) only applies to LH, SM (single-mode) only applies to SM, MM (multi-mode) only applies to MM.
Bidirectional SFP (BIDI) needs to be used in pairs (Type A paired with Type B).

Chapter 6 LED Status Diagnosis
6.1 System level LED
P (power supply): green=dual power supply is normal; Yellow=single path only; Extinguish=no power or undervoltage.
FAULT (red): illuminated=signal contact disconnected (alarm); Extinguish=Normal.
RM (Ring Network Manager): Green=RM activated and redundant ports closed (ring network intact); Yellow=RM activated and redundant ports open (ring network broken but still working); Flashing=ring network configuration error (such as ring port not connected).
Stand by (green): On=Stand by coupling enabled.
6.2 Port LED
LS (link status, green): always on=link valid; Slow flashing (1 time/cycle)=Stand by state; Flash (3 times/cycle)=port disabled.
DA (data, yellow or green): blinking=data transmission and reception.
Note: The port LED color of the RS40 series is green/red, not green/yellow.