ICT RS485 Radio Bridge
The ICT RS485 Radio Bridge replaces a serial cable with a radio link. Two units form a transparent bridge: whatever enters the RS485 or RS232 interface on one side comes out unchanged on the other. Connected equipment needs no modification whatsoever — no drivers, no changed software.
A radio link always requires two units.
Part number 902.172 — Shop — Manual
Features
- Acknowledged transmission with automatic retries — no data loss, even during short radio disturbances
- Buffer of 32 kB per direction with adjustable hold time
- Serial formats 8N1, 8N2, 8E1, 8E2, 8O1, 8O2 — including Modbus RTU with frame mode
- Baud rates from 1200 Bd to 1 MBd; selectable radio data rate between 4.8 and 250 kBd
- Radio link always AES-128 encrypted, custom key can be set
- Configuration via the Wi-Fi web interface (German/English) or over USB
Where it is used
Between a controller or data logger on one side and inverters, sensors or other field devices on the other — wherever an RS485 line would be too long, too expensive, or impossible to lay.
Commissioning in six steps
- Mount and connect — mount both radio bridges, fit the antennas and wire the serial lines to the terminals (RS485: A to A, B to B; or RS232).
- Power up — apply 8 to 24 V DC. The units start within a few seconds.
- Switch on Wi-Fi — press the button briefly. The blue LED lights up and the unit opens the network ICT-Funkbridge.
- Open the web interface — join that network and open
http://192.168.42.1in your browser. - Configure — set the interface (port, baud rate, format) to match the connected equipment, then choose "Apply & save". Both bridges must carry the same radio settings; as delivered they already match.
- Check — the status card shows "partner reachable" with a signal level as soon as the other unit is in range and switched on. Then switch the Wi-Fi off again with the button.
Technical data
| Property | Value |
|---|---|
| Supply | 8–24 V DC |
| Interfaces | RS485 (2-wire, half duplex), RS232, USB (service) |
| Baud rates | 1200 Bd – 1 MBd |
| Serial formats | 8N1, 8N2, 8E1, 8E2, 8O1, 8O2 |
| Radio frequency | 868.3 MHz (SRD band) |
| Radio data rates | 4.8 / 38.4 / 100 / 250 kBd |
| Transmit power | +10 dBm / −0.5 dBm |
| Radio channels | 256 |
| Encryption | AES-128, always active; custom key can be set |
| Buffer | 32 kB per direction |
| Antenna connector | RP-SMA |
| Configuration | Wi-Fi web interface (DE/EN), USB terminal |
| Protection class | IP65 |
| Dimensions / weight | 120 × 58 × 34 mm / 75 g |
| Operating temperature | −40 °C to +85 °C |
| Dimensions (L × W × H) | 120 × 58 × 34 mm |
| Weight | 75 g |
| Material | ABS |
| Colour | grey |
Radio approval: operation in the 868 MHz SRD band is subject to restrictions that depend on country and sub-band, such as duty cycle limits. Please check the requirements of your country of use, especially for applications with a permanently high data load.
Troubleshooting
| Symptom | Possible cause / remedy |
|---|---|
| The web interface shows "no partner" | The other unit has no power or is out of range; check the antenna. Do both units carry the same network ID, radio channel, radio data rate and key? |
| The link is up but no payload arrives | Baud rate and format matching the application? RS485 wires A and B swapped? The right port (RS485 or RS232) selected? |
| The Modbus master reports timeouts | Increase the master's response timeout by the radio latency (typically +200 ms), switch on frame mode, use addressed operation |
Complete manual
Planning, configuration in detail, addressed operation, encryption, status indications, throughput and buffering are all covered in the ICT RS485 Radio Bridge manual — bilingual, with a switch at the top right.
See also
- radino radio modules — if a PCB of your own is to be built
- Interface modules — bridges by cable