IW-1000 vs. IW-485: choosing the right M-Bus interface for your installation
Comparing the serial M-Bus interfaces IW-485 and IW-1000: channel count, load capacity, protocol conversion, and which installation type each fits — plus when the basic IW-CM-M is all you need.
Two products in the M-Bus range get compared constantly because they solve adjacent problems: the [IW-485 series](/product/iw-485) protocol adapter and the [IW-1000 series](/product/iw-1000) high-current physical-layer master. The confusion is understandable — both sit between meters and your system — but they answer different questions.
What each one is
The IW-485 is a *protocol adapter*: it polls M-Bus meters itself (cyclic or triggered reading) and re-serves the data as Modbus-RTU or Modbus-TCP, which makes meters look like registers to a PLC or SCADA system. It is rated for 20 standard loads — a floor, a small building, a machine room.
The IW-1000 is a *physical-layer master* built for scale: 4 independent M-Bus channels and 200 standard loads (300mA @ 34V) in a DIN-rail metal housing, with RS-232 or RS-485 host interface. The host software does the polling; the IW-1000 provides clean, protected bus power and signaling across a large meter estate.
Side by side
| IW-485 | IW-1000 | |
|---|---|---|
| Role | Protocol adapter (M-Bus → Modbus) | High-current physical-layer master |
| Load capacity | 20 standard loads | 200 standard loads |
| Channels | 1 | 4 independent |
| Host interface | RS-232 / RS-485 | RS-232 (IW-1000-232) / RS-485 (IW-1000-485) |
| Polling logic | Built in (cyclic/triggered) | In the host software |
| Typical site | Floor or small building into PLC/SCADA | Tower or campus riser distribution |
And when neither is the answer
- Simple transparent bridging — a PC with M-Bus software just needs the IW-CM-M series converter (5 to 250 loads, transparent RS-232/485).
- IP integration — the IW-ET-M series puts the bus straight onto Ethernet.
- No wired path at all — the IW-GS-G series reads the bus and reports over cellular.
M-Bus Gateways
IWILL IW-485 Series
IWILL IW-485 Series m-bus gateways platform.
M-Bus Gateways
IWILL IW-1000 Series
IWILL IW-1000 Series m-bus gateways platform.
M-Bus Gateways
IWILL IW-CM-M Series
IWILL IW-CM-M Series m-bus gateways platform.
Send meter counts, distances, and the target system — we will confirm the converter set.
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