Black Box PSD-8, PSD-4 Installation, Choosing a Site, Configuring the PSD Printed Circuit Board

PSD-4 AND PSD-8

3. Installation

3.1 Choosing a Site

•The PSD must be installed within five feet (1.5 m) of a grounded AC outlet.

•The PSD must be within 50 feet (15 m) of the equipment that will be attached to the main channel and each sub-channel.

•Allow 36 inches (91 cm) frontal clearance for operating and maintenance accessibility.

•Allow four inches (10 cm) rear-panel clearance for the power and interface cables.

•Side-panel brackets can be used to install the unit in a 19" rack. (The brackets can be removed without harming the PSD.)

3.2 Configuring the PSD Printed Circuit Board

Table 1 on the following page explains each of the configurable jumpers or switches on the PSD printed circuit board. Figures 3 and 4 show the locations of each of the jumpers and switches for the PSD-4 and PSD-8.

There are two EXT. BUFFER switches on the PSD-8. These are extra buffers—not external buffers. Use the extra buffers when the PSD is connected to equipment that cannot accept an external clock from the PSD. The extra buffers compensate for phase differences between clocks. There are many applications where this might be necessary, but one example would be where multiple CSU/DSUs (each attached to its own leased line that provides clocking) are connected to the PSD.

Switch S1 controls the buffer for sub-channels 1 through 4, and switch S2 controls the buffer for sub-channels 5 through 8.

POWER:	DATA:	ACTIVITY:	SUB-CHANNEL	AUTOMATIC:
Lights when	Lights when	Lights when the	DISABLE:	Lights when sub-
the unit is	data is broadcast	sub-channel	Press in the push button	channel has been
receiving	from the main	accesses the	to manually disable a	automatically
AC power	channel to the	main channel.	sub-channel.	disabled.
	sub-channels

Figure 2. The front panels of the PSD-4 (top) and the PSD-8 (bottom).

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