Configuration And Installation; Setting Dte Or Dce; The Installation Procedure - Black Box SHM-NPR User Manual

CHAPTER 3: Configuration and Installation

3. Configuration and Installation

3.1 Setting DTE or DCE

You can configure your SHM-NPR or SHM-NPR/RJ as either a DTE or DCE device.
Just slide the DCE/DTE switch on the top of the unit (shown in Figure 3-1) to
"DCE" (if you are connecting the unit to a DTE such as a PC, terminal, serial
printer, etc.) or "DTE" (if you are connecting the unit to a DCE such as a modem).
You don't need to open the unit's cover to do this.
DCE DTE
Figure 3-1. The DCE/DTE switch.

3.2 The Installation Procedure

On its device side, your SHM-NPR or SHM-NPR/RJ is designed to be plugged
directly into one of the RS-232 serial ports on a terminal, computer, serial printer,
modem, etc. For most applications, this eliminates the need for an RS-232-C data
cable. (If you do need to use one for whatever reason, we recommend a shielded
cable—our EDN25C, for example—that carries all of the pins from which the
SHM-NPR draws power; just make sure to keep this cable as short as possible.) No
power is required from a dedicated AC or DC source, because the unit is powered
entirely by the attached device's control and data signals.
On its line side, your SHM-NPR or SHM-NPR/RJ has a proprietary balanced
4-wire twisted-pair communication-line interface.
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