RS232 <> RS422/RS485 fully isolated converter with self configuration and automatic line turn-around, MI400e-RD

The MI400e-RD is a fully isolated RS232 to RS422/RS485 converter, It automatically detects the direction of the serial data and is totally independent of the communication protocol.

Read more

Product variants

Article Number Product Name
0103-1303-1318-01 + MI400e-RD + Request quote
RS232<=>RS422/RS485 isolated+automatic RS 485 turnaround+Din Rail 100/250 V
0103-1303-1318-02 + MI400e-RD-DC + Request quote
RS232<=>RS422/RS485 isolated+automatic RS 485 turnaround+Din Rail 9/36 V


Thanks to the use of the latest technologies, the MI400e-RD series allows you to install easily and quickly your industrial RS422/RS485 network while making advantage of an increased reliability.

The automatic RS485 line turn-around function contributes to the simplicity of the product installation; the MI400e-RD series automatically detects the direction of the serial data and is totally independent of the communication protocol. Its original mechanism of self configuration frees you from the tiresome operation which consists in the serial parameters setup.

Its dual port feature also makes it possible to connect two RS232 serial devices to a single RS485 bus. 

The MI400e-RD series accept 2 and 4 wires RS422/485 connection, for up to 1200m and support up to 32 bus connected equipments. 

Its small size, design features and its great adaptability make it a really universal product capable to fit in all the needs of the industry.

  • Self-configurable serial link parameters
  • Serial speed up to 2Mbps
  • Optional dual RS232 port in RS485 half-duplex mode
  • Automatic RS485 line turn-around
  • LED display easy RS signals monitiring & diagnostic
  • Din Rail, wall, case and rack universal mounting
  • AC or DC power supply (depending on models)
  • Connectors are compatible with the ACKSYS MI400 series, the RS422/485 screw-in terminal is compatible with the Westermo TM MA-45 & MD-45 products
  • Built-in continuous line surge protection, ESD protection, and lightening protection
  • Robust metal housing, CE standards


One serial RS232 port to one RS422/RS485 port with RS485 mode self line turn-around*, optional dual RS232 slave ports to the RS485 port mode
From 50 bps to 2Mbps
Serial link parameters self configuration (auto-RTS), no switches. Line polarization, termination, echo mode and selection between RS422/RS485 modes are configurable by mini-switches
Male SUB D 9 connector on the RS232 side, 5 pins screw-in terminal on the RS422/485 side, compatible with the Westermo™ MA-45 & MD-45 products and the MI400-x series
LED indication:
TxD, RxD & RTS signals, power supply and RS422/485 line error
Power supply:
AC model works within the 85VAC to 264 VAC 47-440 Hz range and +100VDC to +370VDC (IEC-320 power cord), DC low voltage model works within the +9VDC to +36VDC range (screw-in terminal), consult us for extended power supply range
3 Kveff/1min opto-couplers line isolation, 4 Kveff/1min transformer power line isolation, DC 2 Kveff/1min isolation
Up to 256 RS422 / RS485 tranceivers
Input load:
1/8 UL RS485
EMI-RFI protection:
Built-in continuous line surge protection (50 VCA), ESD protection (15 KVeff) and lightning protection (shock wave & residual effects)
EMC & Security:
NF EN 55022 emission for residential environment, NF EN 61000-6-2 immunity for industrial environment, NF EN 60950 security
6VA for the AC model, 3,5W for the DC model
  • Operating temperature: from 0°C to +65°C
  • Relative humidity: 95% at +25°C
Dimensions, weight:
80 mm (L) x 90 mm (l) x 40 mm (H), 0.5 Kg AC model, 0.4 Kg DC model


Article Number Description
0103-1303-1318-99 din rail mounting
Accessories for din rail mounting and braces for wall and rack mounting delivered with all models

Do you have a request?

Request type
Art. Nr. Product name Remove

You can add another variation to your request

Do you have a request?