Installing the Device
2.4.2 Serial Standard Conversion
1
2
2
3
1
RS232 Device
2
RUGGEDCOM RMC20
3
RS485 Device/Network
Figure 2.5
Serial-to-Fiber Point-to-Point Topology
RS232 Device
Position
State
Notes
1
ON
RS232 <-> Fiber
2
OFF
Serial-to-Fiber Mode
3
ON
Full Duplex
4
OFF
Fiber repeat OFF
RS422 Device/Network
Position
State
Notes
1
OFF
RS422 <-> Fiber
2
OFF
Serial-to-Fiber Mode
3
ON
Full Duplex
4
OFF
Fiber repeat OFF
In this mode, serial data is converted directly into light impulses, and transmitted
over multi-mode fiber optics. The serial standard is selected by position 1 of the DIP
switches: OFF (default) is for RS485/RS422, and ON is for RS232. Position 2 should
be OFF for serial to fiber conversion. Position 6-8 should be configured if RS485
communications are used, in order to have the appropriate turn-around timer shown
below selected. Positions 6-8 do not impact communications in full-duplex mode.
Note
A baud rate lower than 1200 bps is not supported in half-duplex or RS485 mode.
Baud Rate (bps)
DIP6
DIP7
DIP8
Turn-
Around Time
1200-2400
OFF
OFF
OFF
9.5 ms
4800-14400
OFF
OFF
ON
2.3 ms
19200-57600
OFF
ON
OFF
0.58 ms
>57600
ON
OFF
OFF
0.10 ms
Turn-around time is the amount of time after the start bit was transmitted and before the transceiver
changed back to receiver mode.
2.4.2
Serial Standard Conversion
The following illustrates the connections for conversion between RS232 and
RS485/422 devices.
RUGGEDCOM RMC20
Installation Manual, 04/2021, C79000-G8976-1007-10
11
