User Guide

PCB Installation
RCOU3A, RCOS3A – Four-Circuit Loop Start CO Line Interface Unit
6-22 Strata CTX I&M 06/04
RCOU3A, RCOS3A – Four-Circuit Loop Start CO
Line Interface Unit
Circuits per PCB: four loop start CO line circuits
Interfaces with: loop start lines
Older Version(s): RCOU1 (does not have Mu Law/A Law jumper plug)
PCOU2 (does not have ABR circuitry, uses RCTU, K4RCU ABR circuits)
PCOU1 (has ABR circuitry, identical and interchangeable w/PCOU2)
The RCOU3A and RCOU provide ring detection, dial outpulsing, and hold circuitry. Each RCOU
line can be programmed for DTMF or dial pulse signaling and has surge absorbers for secondary
protection.
The RCOU3A and RCOU PCBs are shown in Figures 6-18 and 6-19 and described in Table 6-12.
RCOS Installation (Internal Option)
An RCOS3A PCB can be installed on the RCOU3A or RCOU1A 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 a CO 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 CO when set to position 3. Switches are factory-set at
the 0 (0 dB signal level drop) position.
The RCOS3A and RCOS1A PCBs are shown in Figures 6-16 and 6-17 and described in Tables
6-10 and 6-11.
³ To install an RCOS3A PCB
1. If the Strata CTX system is within one mile of the PBX or CO, 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 RCOS3A female connectors J11, J12, J13, and J14 (Figure 6-16) to the RCOU3A or
RCOU1A male connectors P11, P12, P13, and P14 (Figures 6-18 or 6-19).
3. (RCOS3A 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.
Note The RCOS1A cannot be installed on the RCOU3A.