SATEC RSC232 - Manual (Page 10)

8
5. LED Indicators - located on the top of the converter
LED Indication When Lit
Power Power supply on
TXD / RXD Transmission from RS-232 port to RS-422/RS-485 port
TXD / RXD Transmission from RS-422/RS-485 port to RS-232 port
TX enable Transmit enabled to RS-422/RS-485 port
6. Impedance Matching and Termination Resistors
When an electrical signal travels through two different resistance junctions in a
transmission line, the mismatch will sometimes cause signal reflection. Signal reflection
causes signal distortion, which in turn will contribute communication errors. The solution
to this problem is to establish the same impedance at the line ends as in the line itself by
terminating them with resistors.
It is normally sufficient when the value of the termination resistor equals the characteristic
impedance of the transmission line. The resistors should be added near the receiving
side (between +RXD and -RXD of the converter, and between +RXD and -RXD of the
remote site).
Note: The suggested termination resistor for an AWG #26 cable is 100 ohm. The
suggested termination resistor for a phone cable is 600 ohm.
7. Specifications
Power Supply: ACDC (standard)
12 V DC (optional)
24 VDC "
48 VDC "
85-265 VAC / 88-290 VDC, 50mA
9.6-19 VDC, 200mA
19-37 VDC, 100mA
37-72 VDC, 50mA
Data Rate 300 bps to 115,200 bps
Distance: RS422/RS-485
RS232
up to 4000 ft (1.2 Km)
up to 50 ft (15 meters)
RS-232 DB type female connector supports TXD, RXD, DTR, DSR, RTS, CTS,
GND232
RS-422/RS-485 Terminal Block
Connector supports +TX, +RX, -TX, -RX, GND422
Power Terminal Block Connector supports L \ + (Line), N\ - (Neutral), GND
Switches: SW1
SW2
SW3
full/half duplex mode
baud rate selection
RTS mode
Isolation Protection: power input to PWRGND, 2000V RMS
RS-422/RS-485 to RS-232, up to 2000V RMS
Standards UL1244, CE
LED Indicators Power
RS-232 TXD
RS-232 RXD
RS-422/RS-485 TX Enable
RS-422/RS-485 TXD Enable
RS-422/RS-485 RXD Enable