User Guide

PCB Installation
BSTU/RSTU – Standard Telephone Interface Unit
Strata CTX I&M 06/04 6-11
PCB Installation
BSTU/RSTU – 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): RSTU3, RSTU2, RSTU1
The BSTU and RSTU are basically the same and are interchangeable. Ringer Capacity for the
BSTU is three telephones or devices per circuit. RSTU1, 2 and 3 allow one telephone or device per
circuit.
Notes
• For the system to recognize the DTMF tones generated by a standard telephone (or any other
device connected to a standard telephone port), a DTMF receiver unit must be equipped on the
processor PCB (ARCS subassembly must be installed on ACTU processor of the CTX100.
DTMF receivers are standard on CTX670 processors).
• BSTU and RSTU3 provides Message Waiting (MW). RSTU1 and RSTU2 do not provide MW.
R48S -48 Volt Supply Subassembly Installation
R48S is required for line loop resistance greater than 600 ohms. The maximum loop resistance
allowed with 48S = 1200 ohms; without 48S = 600 ohms.
³ Mate the R48S connectors P6 and P7 (Figures 6-6~6-9) with the R48S connectors P6 and P7
on the BSTU or RSTU.
Note BSTU and RSTU connectors P6 and P7 are positioned so that the R48S only fits in the
proper position.
Figure 6-6 R48S Interface Connectors
BSTU/RSTU Installation
1. Make sure the factory-installed SBSS (BSTU subunit) or SRSS (RSTU subunit) is securely
attached to the BSTU or RSTU (Figures 6-8 and 6-9).
Note “RSTU” can be substituted for “BSTU” in these instructions.
2. Insert the BSTU (component side facing right) into the appropriate slot, and apply firm, even
pressure to ensure proper mating of connectors.
WARNING! The shield on the back of the BSTU and RSTU is designed to protect you from
potentially hazardous ring voltage. Do NOT remove this shield.
P6
P7
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