CHAPTER 3: Installation
7
Follow the instructions in Sections 3.1 and 3.2
before installing the Converter.
3.1 Jumpers and Switches
The Interface Converter has eleven jumpers
(listed in Table 3-3) and one 8-position DIP switch
labeled S1. Switch S1 functions to iprovide
termination on the converter's RS-485 ports.
(Refer to Figure 3-1 for the position of Switch S1
on the printed-circuit board.) When the switch is
in the ON position, a 120-ohm resistor is installed
across the RS-485 pin carrying the particular
signal indicated in Table 3-1. Only two RS-485
devices on a network (usually the first and last
device connected on the bus) will have one of the
DIP switch's pins in the ON position. The rest of
the converters will have these pins set to OFF. Set
this DIP switch's pins to the configuration that
your device requires. See Table 3-1.
3.2 Select DTE/DCE Operation
The RS-232
↔
RS-485 Interface Converter has two
jumper-selectable configurations for selecting
DTE/DCE operation on each port. One is for
connecting RS-485 Data Communications
Equipment (DCE) to RS-232 Data Terminal
Equipment (DTE). The second configuration is for
connecting RS-232 DCE to RS-485 DTE. These
settings are determined by DIP shunt settings
located inside the unit on the printed circuit
board. To set the interfaces, refer to Figure 3-1 for
their location and then set the DIP shunts
according to Table 3-2.
3.0 Installation
Table 3-1. Switch S1.
DIP Switch Pin Signal Terminated by the Resistor
1 Data
2 Receive Timing
3 Send Timing
4 Terminal Timing
5 Data Mode
6 Terminal Ready
7 RTS/CTS
8 Receiver Ready
NOTE
Operating the converter with both ports
configured for either DCE or DTE
operation is not recommended and can
damage the converter.
3.3 Physical Installation
After you configure the Converter, follow these
steps to install it in your application.
1.
Attach the cable from the RS-485 device to the
37-pin female receptacle on the rear panel of
the interface converter case.
2.
Attach the cable from the RS-232 device to the
25-pin female receptacle on the rear panel of
the interface converter case.
3.
Plug the 4-pin power cord into the receptacle
on the rear panel of the case and plug the
power module into an AC outlet.
