Toshiba Strara CTX Series, Installation And Maintenance Manual, Page: 137 / 290

PCB Installation
4-15
Strata CTX I&M September 2002
RCOU3F, RCOS3F – Four-Circuit Loop Start Exchange
Line Interface Unit
Circuits per PCB:
four loop start Exchange line circuits
Interfaces with:
loop start lines
Older Version(s):
PCOU2F
The RCOU3F and RCOU provide ring detection, dial outpulsing, and hold circuitry. Each RCOU line
can be programmed for DTMF or dial pulse signalling and has surge absorbers for secondary
protection.
The RCOU3F and RCOU PCBs are shown in Figures 4-13 and 4-14 and described in Table 4-9 .
RCOS Installation (Internal Option)
An RCOS3F PCB can be installed on the RCOU3F for four more loop start lines (for a total of eight
lines–the RCOS circuits provide the same options as the RCOU). Each RCOS circuit has surge
absorbers for secondary protection.
Excessive loudness which is caused by close proximity to an Exchange or PBX telephone can be fixed
through the RCOS and RCOU decibel (dB) Pad switches. RCOS dB switches SW501, SW601,
SW701, and SW801 and RCOU dB switches SW101, SW201, SW301, and SW401 provide a -3 dB
signal level drop between the PBX and Exchange when set to position 3. Switches are factory-set at the
0 (0 dB signal level drop) position.
The RCOS3F PCB is shown in Figures 4-11 and 4-12 and described in Table 4-8 .
➤
To install an RCOS3F PCB
1. If the Strata CTX system is within one mile of the PBX or Exchange, set the RCOS dB Pad
switches SW501, SW601, SW701, and SW801 to the 3 (-3 dB signal level drop) position. Set the
RCOU dB Pad switches to position 3 also.
Note
RCOU male connectors P11, P12, P13, and P14 are positioned to allow installation of the
RCOS only in the proper position.
2. Mate the RCOS3F female connectors J11, J12, J13, and J14 ( Figure 4-11 ) to the RCOU3F male
connectors P11, P12, P13, and P14 ( Figures 4-13 or 4-14 ).
3. (RCOS3F only) For Mexico, the U.K, or Asia, insert the short jumper plug on the A Law side. For
the U.S. and Canada, no plug is required. (No plug is the Mu Law assignment).
4. Apply firm, even pressure to the RCOS to ensure proper mating of connectors.