Endress+Hauser RN42 Active Barrier

Fits 0/4–20 mA HART loops that need a 1-channel, HART-transparent active barrier with wide-range 24–230 V AC/DC supply on a DIN-rail mount — not a passive isolator alone.

Key advantages

HART-transparent active barrier — 1-channel 0/4–20 mA / HART in and out.
Wide-range supply — 24–230 V AC/DC for mixed panel power standards.
DIN-rail form — compact cabinet mount for loop isolation and powering.
Optional SIL 2 — order-code / certificate dependent functional safety.

Typical applications

Isolating and powering 4–20 mA HART field transmitters from the control cabinet.
Panels that need one wide-range barrier covering AC and DC supplies.
Loops specifying optional SIL 2 barrier certificates.

Selection guide

Function — 1-channel active barrier, HART-transparent, wide-range supply.
Input — 0/4–20 mA / HART.
Output — 0/4–20 mA / HART.
Supply — 24–230 V AC/DC (wide-range). Confirm panel AC vs DC before ordering.
Housing / mount — DIN rail.
SIL — Optional SIL 2 (order-code / certificate dependent).
Approvals — CE; ATEX; IECEx; optional SIL/Ex.

Common mistakes

Ordering a passive isolator when the loop needs an active barrier that can power the field device.
Assuming SIL 2 is on every unit — SIL is optional; lock the code and certificate on the quote.
Mixing Ex / non-Ex builds; ATEX/IECEx coverage is order-dependent.
Ignoring that input and output are both 0/4–20 mA HART-transparent — confirm HART pass-through is required for your handheld / DCS.
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When to RFQ / what to tell us

Loop signal (0/4–20 mA) and whether HART transparency is required.
Available supply (must fit 24–230 V AC/DC) and panel voltage type.
SIL 2 yes/no and any Ex / area marks required (ATEX, IECEx).
Channel count needed (this SKU is 1-channel) and quantity / ship-to country.

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Specs

Spec	Value
SKU	141040
Brand	Endress+Hauser
Model	RN42
Product type	barrier
Function	1-channel active barrier, HART-transparent, wide-range supply
Input	0/4–20 mA / HART
Output signal	0/4–20 mA / HART
Supply voltage	24–230 V AC/DC (wide-range)
Housing / mount	DIN rail
Approvals	CE; ATEX; IECEx; optional SIL/Ex
SIL	Optional SIL 2
Notes	Specs from Endress+Hauser RN42 TI / product page. Exact Ex and SIL marks depend on ordered configuration.

Documents

Endress+Hauser RN42 technical information (PDF)

FAQ

Q: Active barrier vs passive isolator — which do I need? A: Use the RN42 when you need a 1-channel active barrier that is HART-transparent on 0/4–20 mA with wide-range 24–230 V AC/DC supply. If you only need galvanic isolation without active barrier capability, say so in the RFQ and we will steer the selection.

Q: Is SIL 2 included by default? A: No. SIL 2 is optional. State SIL / safety-loop needs on the quote so the matching code and certificate are confirmed.

Q: Which approvals can I claim? A: Only those in the OEM documentation and ordered configuration: CE, ATEX, IECEx, and optional SIL/Ex. We do not invent marks.

Q: What should I send for a quote? A: Signal type, HART yes/no, supply voltage available, SIL / Ex marks required, quantity, ship-to country. Compatible with systems using Endress+Hauser RN42 if you need a drop-in check — we do not claim authorized-dealer status.