Dte/Dce Control; Fiber Optic Transmitter/Receiver (Optional) - GE F485 Instruction Manual

DTE/DCE control

Fiber optic transmitter/receiver (optional)

Mounting
6
The DTE/DCE setting reverses the transmit/receive data lines on the RS232 side. For
communications between a computer and a slave device, DTE (direct) should be selected.
When connecting the F485 converter to a modem or other data communications
equipment, DCE should be selected. Another application which requires DCE is when two
F485 converters are connected back-to-back i.e. converting RS232 to RS485 or fiber and
then converting the RS485 or fiber back to RS232. In this case, the second F485 must be
set to DCE control.
Selecting switch settings other than those shown above will cause unpredictable results.
Fiber optic transmissions provide an ideal solution for areas where RS485 communications
via a twisted pair have traditionally caused problems. Fiber is immune to electrical
interference and provides total isolation.
The fiber optic transmitter and receiver used in the F485 converter utilize 820nm
wavelength technology and are designed to operate with 50/125µm, 62.5/125µm and
100/140µm fiber sizes using ST terminated cables. The ST connections provide repeatable
connections within 0.2 dB typically. The transmitter/receiver pair will typically work with
fiber lengths up to 1km.
Ensure the dust covers are installed when the fiber is not in use. Dirty or scratched
connectors can lead to high losses on a fiber link.
Observing the transmitter output under magnification may cause injury to the eye.
Installation
Two different mounting arrangements are possible. The first is by using the two mounting
holes inside the plastic case along with the mounting screws supplied. To remove the
plastic top, simply press in the two plastic tabs on either end of the box and then pull off
the top. The second and less permanent method is to use the Velcro material supplied for
attachment to the side of a computer or desk. Where possible, ensure that the LEDs on the
front panel are visible. The LEDs are a very valuable tool when troubleshooting a problem.
F485 COMMUNICATIONS CONVERTER – INSTRUCTION MANUAL