Connect Tech DFlex-4/104, User Manual

Page: 68 / 82

4-18 Chapter 4: Appendix F - RS-485/422 Option
DFlex-4/104 User’s Manual, ver. 0.04
RS-485/422 SLIM
You can use the RS-485/422 SLIM in 2 wire and 4 wire multi-
drop configurations where the RS-485 line drivers are disabled to
allow other devices access to the line.
Your DFlex-4/104 adapter does not provide DIP switches to
control the driver enables for the RS-485 SLIM. Instead, the DTR
signal is used to gate the control. If DTR is asserted, the drivers
are always enabled. If DTR is not asserted, then the driver will be
enabled only when RTS is asserted. To disable the RS-485 line
driver you must
not assert DTR and RTS.
Also, the receivers on the RS-485 SLIM are biased high through
fixed resistors. Please refer to
Figure 14 for a partial schematic
of the RS-485/422 SLIM circuit, while Table 9 shows the pinouts
for the SLIM sockets found on the DFlex-4/104 adapter.
Your DFlex-4/104 adapter is very sensitive to static electricity.
Make sure that before you remove the card from the anti-static
shipping bag, you wear an anti-static wristband. When you
remove the board from the anti-static bag, handle it only by the
edges and place it on the anti-static bag or an anti-static mat.