Toshiba CTX28 manual PS-1 Backup Power Option, RBSU/RBSS Installation, Run Related Programs

ISDN Interfaces

RBSU/RBSS Interface Units

PS-1 Backup Power Option

The RBSU provides an optional backup power supply, R40S, that will supply backup power to TE devices in the event of an AC power loss. This power backup option only applies to RBSU or RBSS circuits that are configured in the NT mode. See Figure 7-13to install the R40S.

Also the Strata CTX system must have battery backup to allow the R40S power backup function to operate. The R40S power supply is an ISDN, PS-1 type power unit which means it supplies power to TE devices on the RBSU/RBSS transmit and receive wire pairs as shown in Figure 7-10. This power arrangement is also known as phantom power.

Each of the four circuits on RBSU/RBSS can be connected to share the R40S using option switches on the PCBs (see Table 7-8). Before using the R40S as a backup power source, make sure the TE devices do not require more power than the R40S can supply and the TE is compatible with the ISDN PS-1 power arrangement.

TE		RJ45 Pin Nos. on			RBSU
		RBSU or RBSS
		NT circuit
	Pin 3	RX +	Pin 3
					R40S PS-1
TE Device	Pin 6	RX -	Pin 6
					Power
Power sink	Pin 4	TX +	Pin 4
					Source
	Pin 5	TX -	Pin 5
		RJ45 Pin Nos.
		on TE device		4774

R40S Power Limits:

Voltage: 33.3VDC to 38.85VDC maximum

Current: 100mA maximum (25mA maximum per each RBSU/RBSS circuit)

Figure 7-10 Power Limits of the Backup Power Supply

RBSU/RBSS Installation

Step 1: Run Related Programs

Run all ISDN programs related to RBSU/RBSS BRI circuits prior to installation of the PCBs. This enables the circuits to operate immediately upon insertion. ISDN BRI programs are explained in the Strata CTX Programming Manual under the ISDN tab.

Step 2: Set Option Switches/Jumpers

Set all option switches and jumpers on the RBSU and RBSS PCBs before plugging the RBSS onto the RBSU or inserting the RBSU into the system. RBSU/RBSS switch/jumper information and locations are shown in Figures 7-11, 7-12and Table 7-8.

7-16 Strata CTX I&M 06/04