Section 365–336–202
6
6.
INSTALLER CONNECTIONS
Installer connections are made to the channel unit via connectorized cable connectors that are part of the chan-
nel bank assembly. Refer to the appropriate channel bank installer practice for pin assignments.
7.
OPTIONS
The 3653–36 is equipped with push button, DIP, and slide switch options that are used to condition the module
for proper application and operation. Refer to Figure 4 and Table 1 for the location of these options while reading
the following instructions.
7.1
Slide-Switch S1 – Sealing Current Control
When S1 is placed in the SX (Simplex) position the 3653–36 provides sealing current to the 4W facility. In the SX
position the module also provides an automatic ZAP when it is first plugged in. When switch S1 is placed in the
LP (Loop) position, the simplex leads of T1 and T2 are shorted together, which allows the channel unit to loop
sealing current applied from the other end of the analog facility. The OPN (Open) position is used when no seal-
ing current source or sink is required.
7.2
Switches S2 and S3 – XMT ATTN (Transmit Prescription Attenuation)
Switches S2 and S3 form a 9-section DIP switch that provides up to 32.5dB of attenuation, in 0.1dB steps, to ac-
commodate various input TLPs. Refer to Transmit Alignment in Part 8.
7.3
Switches S4 and S5 – RCV ATTN (Receive Prescription Attenuation)
Switches S4 and S5 form a 9-section DIP switch that provides up to 32.5dB of attenuation, in 0.1dB steps, to ac-
commodate various output TLPs. Refer to Receive Alignment in Part 8.
7.4
Switches S6 and S7 – ELL GAIN/ATTN (Equal Level Loopback Prescription Gain/Attenuation)
Switch S6 is a 6-section DIP switch that provides up to 31.5dB of equal level loopback in 0.5dB steps. S7 is a
two-position slide switch to set equal level loopback for gain or attenuation. Refer to Equal Level Loopback Align-
ment in Part 8.
7.5
Switch S8 – Loopback Controls
S8 is a 3-position DIP switch that controls the loopback features of the unit. To disable the tone-activated loop-
back feature completely, set S8–3 to DIS; to enable the tone-activated loopback feature, set S8–3 to LB. To allow
for a 4-minute automatic loopback timeout, set S8–2 to 4; to allow for a 20-minute timeout, set S8–2 to 20. To
allow for no (infinite) loopback release timeout, set S8–1 to DIS; to allow for a 4 or 20-minute automatic timeout,
set S8–1 to TO.
7.6
Switch S9 – MLB (Manual Loopback)
The MLB front-panel switch (S9) is a ‘push-on/push-off’ push-button switch. With each actuation of the MLB
switch, the channel unit will alternate between loopback and the normal operating mode. When placed into loop-
back via the manual switch, the channel unit will remain in the loopback state, regardless of the optioning of S8
loopback controls.
7.7
Switch S11 – T-SIG, R-SIG (7 5/6-Bit or 8-Bit Encoding and Decoding)
S11 is a 2-section DIP switch. Place switch S11–1 (T-SIG) and S11–2 (R-SIG) to the ON position for a 7 5/6-bit
encoding/decoding scheme for end-to-end compatibility with E&M channel units. In this scheme an off-hook (logic
1) is transmitted on the A&B signaling bits to the far end. Place switch S11–1 (T-SIG) and S11–2 (R-SIG) to the
OFF position for a full 8-bit encoding/decoding scheme which provides a greater signal-to-noise ratio than the 7
5/6-bit scheme and does not transmit an off-hook to the far end.