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CHAPTER 3: Installation
3. Installation
3.1 Standalone and Rackmount Versions
The SHM-B Parallel is available in a standalone version and a rackmount version.
The standalone transmitter and receiver are packaged in small, lightweight ABS
plastic cases and equipped with wallmount transformers, for use on a desktop or
shelf. The printed circuit card can be removed from the case and the transformer
discarded, enabling the card to be installed in a rack if desired. The rackmount
version slips easily into an 8- or 16-card rack or enclosure.
3.2 Connectors
Each unit is equipped with a DB25 connector and a 4-wire terminal block.
The DB25 connector conforms to the IBM
®
PC parallel interface pinout, using
the Centronics
®
interface protocol. The 4-wire terminal block is the serial interface
to the twisted-pair line.
3.3 Installation Procedure
Before installing the receiver or transmitter, make certain the unit is not plugged
into the power source, and the equipment that you are going to attach to them is
turned off.
Each unit is ready to use as it comes from the factory. No changes are necessary
when used as a modem set to transmit data from a parallel device to another
parallel device at distances of up to 1.1 mile (1.8 kg). However, for installations in
which the loop length exceeds 1.1 mile, data corruption may occur due to
excessive line noise and/or capacitance. In this case, reduce the transmission baud
rate, using the configuration procedure described in
Section 3.6
.
Installation is accomplished in the following three steps:
1. Connect Cabling
For installation, connect a 4-wire twisted-pair cable between the transmitter and
the receiver.