Toshiba Strara CTX Series, Installation And Maintenance Manual, Page: 134 / 290

PCB Installation
4-12
Strata CTX I&M September 2002
RSTU3 – Standard Telephone Interface Unit
Circuits per PCB:
eight standard telephone circuits
Interfaces with:
standard telephones
voice mail ports
off-premises stations
other similar devices
alternate BGM sources
auto attendant digital announcer
message waiting lamp
Older Version(s):
RSTU1–80-VRMS sine wave ring generator, optional R48S unit increases the loop
voltage from -24VDC to -48VDC, extending the loop length (including the resistance of
the phones from 600 ohms to 1200 ohms.
PSTU–190V P-P or 130V P-P W1 jumper
Only one telephone (or device) can be connected to a RSTU3 port. If more than one telephone or
device is connected to a port, ringing or message waiting may not function. RSTU3 only provides a
90-volt square wave message waiting generator to drive standard telephone 90V message waiting
lamps.
Notes
◆
For the system to recognise the DTMF tones generated by a standard telephone (or any other
device connected to a standard telephone port), a DTMF Receiver Unit (RRCS -4, -8, or -12) must
be installed on the processor PCB.
◆
Most standard telephones and two-wire devices require the 190V P-P level; however, some
devices may experience ring-trip with 190V P-P and should be set for 130V P-P.
R48S -48 Volt Supply Installation (Internal Option)
➤
Mate the R48S connectors P6 and P7 ( Figures 4-8 ~ 4-10 ) with the R48S connectors P6 and P7 on
the RSTU or RSTU3.
Note
RSTU connectors P6 and P7 are positioned so that the R48S only fits in the proper position.
Figure 4-8 R48S Interface Connectors
P6
P7
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