_UMD - Model 153
Isolated RS232 to RS422/485 Interface Converter

The Unique Micro Design Model 153 is an electrically isolated bidirectional interface converter for RS232 to RS422 / RS485 signals. The Model 153 is ideally suited for driving serial data over long distances, especially where differing ground potentials may occur between connected nodes or where protection from electrical interference is required. When used in RS485 multidrop mode (master - slave), the transmitter is enabled by asserting either the Data Terminal Ready (DTR) or Request to Send (RTS) lines on the RS232 interface (jumper selectable).
  • RS232 to RS422 / RS485 bidirectional interface converter.
  • Jumper Selectable RS422 or RS485.
  • Electrically isolated to 200 Volts (Transorb® protected).
  • UMD standard DB9 Socket DCE serial connector ( mates with UMD products ).
  • Powered from regulated 5 volts DC connected on RS232 DB9 connector or
  • Unregulated 7 - 9 volts DC through terminals on the circuit board.
  • Circuit Board designed to mount on Standard Pattern Flush Mounting GPO wall plates.

  • 12 months warranty.
  • Designed and manufactured in Australia by Unique Micro Design.


Dimensions50 x 70 x 20 mm
(loaded circuit board)
Input Voltage5 Volts DC regulated on DB9 connector
7 - 9 Volts DC unregulated on screw terminals
Input Current60ma
Communication Ports
RS232DB9 Socket (DCE)
Transmission Speed38,400 baud maximum
RS422/485Screw Terminal, 4 way
LEDPower, transmit data and receive data
Ordering Information and Pricing
Part Number Model Number Description RRP
[A] M153 Kits
9-0153-100-3 M153 M153 with D9 Plate and Terminators $165.00 U3
9-0153-200-9 M153-200 M153 with Terminators $159.50 U3
[B] Accessories
4-0041-100-1 M153, D9 Standard Plate $12.10 U3
1-6004-104-2 PPI6D1000-F Plug Pack In-Line 6V 1A for M153 $27.50 U3
6-0450-800-6 M450-TP UTC Teminator Pack $5.50 U3
2-5109-020-4 CA109-2 D9P to D9S 2m $16.50 U1
2-6149-020-2 CA6149-2 M153 to D9 Ser w UPP $71.50 U1
2-6150-020-1 CA6150-2 M153 to D25 Ser UPP $71.50 U1
[C] Documentation
6-0153-992-7 DOC-M153-PD Product Description
6-0153-993-5 DOC-M153-UM User Manual